Iran says it has received a US response to its latest peace proposal. The response, delivered via Pakistan, is now under review, according to Iranian state-linked media.
The US has not confirmed the reply. On Saturday, President Donald Trump said he would review Iran's plan but doubted it would be acceptable.
Iran's 14-point proposal calls for Washington to withdraw forces from near its borders, end the naval blockade of Iranian ports, and halt all hostilities, including Israel's offensive in Lebanon. It also demands a deal within 30 days.
Trump told reporters in Palm Beach, Florida, that military strikes against Iran remain a possibility. "If they misbehave, if they do something bad," he said, adding that the US is "not leaving" the conflict.
The standoff comes as the 60-day deadline for Congressional approval of the US military action approaches. Republican lawmakers are growing frustrated with what many call a costly war with unclear objectives.
Senator Josh Hawley of Missouri has called for redeploying forces, while Senator Lisa Murkowski of Alaska warns against an abrupt withdrawal that could leave Iran's critical capabilities intact.