Earlier, Iranian Foreign Minister Abbas Aragchi held talks with mediator Pakistan, saying afterwards he had shared Iran's position on ending the war but was yet to see whether the US was "truly serious about diplomacy".BBC reported.
Diplomatic efforts have stalled despite Trump's extension of a ceasefire that had been due to expire on 22 April to allow talks to continue.
Both sides have been locked in a standoff over the Strait of Hormuz, with Iran restricting passage through the key shipping route in the wake of the US and Israel commencing strikes in February, as well as over Tehran's nuclear ambitions.
The US has since increased its naval presence in the strait - through which roughly a fifth of the world's oil supply passes - to block Iranian oil exports.
