U.S. President Donald Trump on Thursday accused Iran of doing a "very poor job" of allowing oil through the Strait of Hormuz and of breaching the terms of their two-week ceasefire agreement.

Pakistan was poised on Friday to host Iranian and U.S. delegations for negotiations in its capital, although Tehran's participation remained uncertain after deadly Israeli strikes on Lebanon threatened this week's temporary truce.

U.S. President Donald Trump told NBC News on Thursday he was "very optimistic" about a peace deal with Iran after their ceasefire, and that Israel was "scaling back" strikes in Lebanon.

U.S. Vice President JD Vance on Wednesday urged Iran not to let the fragile ceasefire deal fall apart over Israel's attacks on Lebanon, days before he is due to lead talks with Tehran in Pakistan.

U.S. President Donald Trump said late Wednesday that U.S. forces deployed near Iran would remain stationed in the area until a "real agreement" is reached, as Washington enters a fragile two-week ceasefire with Tehran.

Iran's ambassador to Pakistan deleted a social media post saying an Iranian delegation would arrive in Islamabad on Thursday night, a move an embassy official later told AFP had been sent prematurely.

Iran's parliament speaker said Wednesday that a ceasefire and talks with the United States were "unreasonable" because of violations of Tehran's 10-point truce plan, including continued attacks in Lebanon, a drone entering Iranian airspace and a denial of the country's right to enrichment.

The U.S., Israel and Iran agree that a ceasefire is now in effect, but they're contradicting each other and themselves in terms of what's actually been agreed and what happens now, U.S. news portal Axios reported on Wednesday.

The U.S. has agreed to a two-week ceasefire with Iran proposed by Pakistan, U.S. President Donald Trump said Tuesday night.

Prime Minister of Pakistan Shehbaz Sharif said Tuesday that "diplomatic efforts for peaceful settlement of the ongoing war in the Middle East are progressing steadily, strongly and powerfully with the potential to lead to substantive results in near future," despite the unprecedented tensions in the region.