The Iranian foreign minister, Abbas Araghchi, arrived in Oman on Saturday for talks on the future of the Strait of Hormuz. The visit came a day after U.S. officials said they expected Iran to publicly declare an end to attacks on commercial ships in the waterway.

Though a cease-fire was signed by the two countries last month, President Trump and Iran’s supreme leader have continued to trade threats amid frequent flare-ups of fighting. In a written message on Saturday, Ayatollah Mojtaba Khamenei vowed revenge for the killing of his father and predecessor, Ayatollah Ali Khamenei, saying it was the “demand of our nation.”

The rhetoric furthered the uncertainty hanging over the fragile truce. While the Trump administration had said the cease-fire would fully lift Iran’s blockade of the Strait of Hormuz, a vital waterway for global oil and gas shipments, that has yet to be borne out.

Instead, Iranian forces have fired on ships traveling on routes they deem unacceptable, prompting the U.S. military to retaliate with attacks on Iranian military sites. The United States also revoked a sanctions waiver that had temporarily permitted the sale of Iranian oil.

Some of the ships were traveling along a route close to Oman’s coastline guided and protected by the United States. Iran has insisted that its waters are the only permissible route through the strait, essentially bringing marine traffic under its control.

After days of clashes over the strait, U.S. officials said Friday that they expected Iran to issue a public statement in the coming days acknowledging that all channels through the Strait of Hormuz were open, and that Iranian forces would cease shooting at passing ships.

The officials, who spoke to reporters on the condition that they not be identified, said that if Iran did not issue the statement, and stick with it, “we’re not going to have a good outcome for them.”

The Iranian government did not immediately comment. In a statement on Friday night, Esmaeil Baghaei, the Iranian foreign ministry spokesman, said Mr. Araghchi’s visit to Oman would include a meeting with Badr Albusaidi, the Omani foreign minister, and discussion of facilitating “safe navigation through the Strait of Hormuz.”

So far, threats by President Trump and bombardment by American warplanes have not succeeded in forcing Iran to relax its grip on the strait. Instead, both countries are now engaged in a simmering standoff — neither all-out war nor peace — with Mr. Trump saying on Friday that June’s cease-fire agreement was “over.”

Later, Mr. Trump added a threat on social media, vowing that “1000 Missiles are Locked and Loaded and aimed at the Islamic Republic of Iran” should the country make good on its threats to assassinate him or try to do so. U.S. law enforcement says Iran has devised several plots to kill him, as well as other American government officials, over the years.

In a seeming retort, Iran’s supreme leader, Ayatollah Khamenei, said that the country would seek revenge for his father. “We pledge that we will avenge your pure blood and the blood of all those martyred,” he wrote in a message published in Iranian state media on Saturday.

It is his first statement since a weeklong funeral for the elder Ayatollah Khamenei, culminating in his burial in Mashhad on Thursday. Millions turned out for processions and ceremonies across several cities in Iran and Iraq.

The new supreme leader was absent from the funeral and has been neither seen nor heard in public since being appointed to succeed his father’s authoritarian rule in early March, though he has occasionally released written statements. He is believed to have been wounded on the first day of the war, according to Iranian and Israeli officials.

The latest round of fighting began this week after Iran fired on three ships traversing the strait, U.S. officials said, with some of those vessels linked to the Persian Gulf countries of Qatar and Saudi Arabia, both U.S. allies.

U.S. forces retaliated with two days of heavy bombardment, attacking about 170 Iranian military targets, according to the U.S. military. On Friday, a spokesman for the Iranian health ministry said on social media that at least 17 people were killed in the attacks. Iran’s state television identified at least eight of the dead as soldiers.

Iran fired waves of ballistic missiles and drones at Kuwait, Bahrain and, for the first time since the beginning of the truce, Jordan.

The battle of wills in the Persian Gulf has reinforced skepticism that Mr. Trump can reach a broader pact with Iran to rein in its nuclear program, a stated aim of the U.S.-Israeli war on Iran that began in late February. Under the June cease-fire agreement, the two countries were supposed to negotiate a more comprehensive agreement in 60 days — a time frame that appears increasingly remote.

Oman has circulated its own proposal for jointly administering the Strait of Hormuz alongside Iran, including the potential imposition of service fees on transiting ships. The plans would be a significant change from the prewar status in the strait, when boats generally passed freely.

Leily Nikounazar and David E. Sanger contributed reporting.

Mahmoud Abbas, the longtime president of the Palestinian Authority, on Thursday set Palestinian parliamentary elections for this November in what would be the first such vote in more than two decades.

The announcement appeared to be part of an effort by the Palestinian Authority, which exercises limited self-rule over parts of the Israeli-occupied West Bank, to convince the United States and European and Arab nations that it was willing to make changes to its system. The authority has been dogged for years by accusations of corruption, and U.S. officials have said that it can play a meaningful role in postwar Gaza only if it can carry out a significant overhaul.

But some Palestinians and analysts questioned whether the elections would happen at all. Mr. Abbas called a similar election in 2021 only to abruptly cancel the vote after it became clear his hold on power was under threat. Mr. Abbas’s elections decree does not mention a presidential vote, which could threaten his position at the top.

“We need elections, and we would love for the opportunity to vote,” said Mahzouz Shalaldeh, 41, a resident of a village in the Hebron area in the southern West Bank. “But I just can’t see them actually taking place.”

Mr. Abbas, 90, was elected to office in early 2005 after the death of his predecessor, Yasir Arafat. As the leader of Fatah, the ruling party in the West Bank, Mr. Abbas has consolidated his authority by ousting rivals, sidelining the judiciary and cooperating with Israel on security.

His announcement comes at a volatile moment for the West Bank, where violence has sharply risen since the war in Gaza began and numbers of settler outposts have surged. Extremist Israeli settlers frequently attack Palestinians and are rarely held accountable.

The decree issued Thursday calls on Palestinians in the West Bank, Gaza and East Jerusalem to participate in parliamentary elections on Nov. 28.

By calling for new elections, Mr. Abbas was likely hoping to answer international demands to overhaul the Palestinian Authority, according to analysts of Palestinian politics.

“Abbas feels that by running these elections, there will be an image of reform,” said Ghaith al-Omari, a former adviser to Mr. Abbas. “But there’s a lot of skepticism, because we’ve seen this movie before.”

Mr. al-Omari said Mr. Abbas might feel more comfortable holding the vote because he last month had issued a new elections law aimed at excluding Hamas and Palestinian Islamic Jihad, his rivals, from running. But he could still face pressure from rivals within his own party, he added.

Under the new law, candidates must abide by the political program of the Palestine Liberation Organization, the body that negotiated a series of deals in the 1990s leading to the creation of the Palestinian Authority. In 1993, the P.L.O. recognized Israel’s right to exist, a position that Hamas and Islamic Jihad adamantly oppose.

Mr. Abbas’s critics have warned that, despite his gestures toward change, he helped elevate a member of his family to a major leadership role in the party in May, prompting accusations of nepotism and backroom dealing.

Hamas did not immediately issue an official statement on Mr. Abbas’s decree.

The last time the Palestinians went to the polls, in 2006, it led to a brittle governing body, international isolation and, eventually, violence.

In the elections that year, a rival party representing Hamas trounced Fatah in legislative elections, leading to a year and a half of uneasy power sharing.

The United States and much of the West refused to work with the unity government because Hamas, which they designated a terrorist organization, would not accept demands such as renouncing violence.

Then Fatah and Hamas fought a brief civil war in the coastal territory of the Gaza Strip. It ended in June 2007, with Hamas seizing control there after routing forces loyal to Mr. Abbas and confining his authority to parts of the West Bank.

Holding legislative elections in Gaza is likely to be challenging, given the enormous devastation in the territory from years of war. But the Central Elections Commission of the Palestinian Authority has already studied ways to organize the vote amid the conditions there, according to an internal document produced by the commission.

Israel could also try to obstruct the elections from taking place by restricting movement of voters in the West Bank, arresting candidates and refusing to coordinate the delivery of supplies from the West Bank to Gaza. The Israeli prime minister’s office did not respond to a request for comment.