Oil tankers sailed through the Strait of Hormuz and the United States said it lifted its blockade on Iran on Thursday as an interim deal to end the war took effect, though key issues are still unresolved between the two countries.Oil prices dropped to their lowest level since March 2, as analysts said exports through the strait, which handles about one-fifth of global oil supply, could return to normal in the coming months.

But Israel continued its war against Hezbollah in Lebanon, raising questions about whether the agreement would hold.

In Washington, some of President Donald Trump's Republican allies in Congress questioned whether he had given up too much in order to end the conflict, which is unpopular with US voters.

Iran's Supreme Leader Ayatollah Mojtaba Khamenei said Trump signed the deal "out of desperation" and signaled that upcoming talks over Iran's nuclear program – Trump's stated reason for starting the war – would not be easy.

"If the American side wants to be too demanding, we will not accept it," he said in a written message.