Iran said on Monday that it was holding talks with Oman on temporarily reopening the Strait of Hormuz, the critical shipping lane in the Persian Gulf, as mediators rushed to tamp down the prospects of renewed war between the United States and Iran.

Esmaeil Baghaei, the Iranian foreign ministry spokesman, said at a news conference that there were no direct U.S.-Iran talks at the moment, suggesting that a broader peace deal was not in the offing for now. Instead, he said, the talks with Oman were narrowly focused on negotiating a new route for ships to traverse the strait.

“The focus of the negotiations with Oman will be on this issue, while the matters relating to Iran and the United States will have to be examined in later stages,” Mr. Baghaei said.

President Trump lashed out at Iran’s government on Monday, calling its leaders “unbelievably duplicitous” and suggesting that the United States and Iran were, in fact, discussing a solution to resolve the problems in the Strait of Hormuz.

If the talks are successful, they could pave the way for the United States and Iran to return to a broader cease-fire after an earlier deal collapsed in July amid tensions over the Strait of Hormuz.

Mr. Trump abruptly canceled a threatened assault on Iran over the weekend, saying there could be progress in reopening the strait, a major waterway for global energy exports blockaded by Iran for months now. He also cited pleas for calm by regional allies like Saudi Arabia.