US must return to interim deal, no ceasefire extension talks, senior Iranian source says

However, efforts to secure a lasting peace have hit an impasse over a range of issues, including disagreements over the Strait of Hormuz.

Tehran says the vital shipping route will remain closed as long as the U.S. does not change its behaviour and accept Iran's conditions to end the war, including the unfreezing of Iranian funds overseas.

After the start of the war, which began with U.S.-Israeli strikes on Iran on February 28, Tehran effectively shut the strait, through which a fifth of the world's oil and liquefied natural gas was shipped.

Iranian Foreign Minister Abbas Araqchi said on Sunday that Iran and the U.S. are not engaged in talks and Tehran will not start them as long as Washington breaches the interim deal, adding that messages are being exchanged via intermediaries Pakistan and Qatar.