People across the Middle East waited uneasily on Saturday for a decision from President Trump about a proposal to end the war with Iran, as the United States reaffirmed its resolve to emerge with a deal he finds acceptable.

Mr. Trump said on social media on Friday that he was meeting with advisers at the White House Situation Room to make a “final determination” about the proposed deal, but that meeting ended with no announcement.

Mr. Trump has zigzagged on his positions during the negotiations, vacillating between talk of progress on a deal and threats of renewed strikes.

Later on Friday evening, Iran said there was still “no final agreement” with the United States. Esmaeil Baghaei, the Iranian Foreign Ministry spokesman, told state television that while “message exchanges are of course ongoing,” a deal was not yet in hand.

Some people in Iran who had hoped that the war could lead to the end of the Islamic Republic’s authoritarian rule said they were disillusioned and indifferent to the idea of a potential agreement.

“We know that even if there is one, we will not receive any benefits from it,” said Ali, a 43-year-old engineer from Mazandaran Province in northern Iran, who asked to be identified only by his first name, fearing government retaliation.

“It would mostly serve to guarantee the survival of the Islamic Republic,” he added.

Some details of the proposal — which has yet to be made public — were described by several officials briefed on them or involved in the talks, who spoke on condition of anonymity because of the sensitivity of the diplomacy.

The proposal appears to involve few immediate concessions from Iran, despite Mr. Trump’s insistence that he has won a resounding victory over his adversaries.

It would effectively end the U.S.-Israeli military campaign against Iran in exchange for Iran lifting its blockade of the Strait of Hormuz, a crucial waterway for oil and gas shipping that Iran has closed since the early days of the war, rattling energy markets.