The delegation was led by Iranian parliamentary speaker Mohammad Bagher Ghalibaf, along with Foreign Minister Abbas Araghchi and other security and economic officials, state broadcaster IRIB said on its website. It reiterated Iran's position, however, that talks would only begin if Washington accepts Iran's preconditions.

Ghalibaf earlier set a ceasefire in Lebanon, where Israel has attacked militant group Hezbollah, and the "release of Iran's blocked assets" as conditions for the start of negotiations with the US delegation led by Vice President JD Vance.

Official sources say the Islamabad talks will cover sensitive points, including Iran's nuclear enrichment and the free flow of trade through the Strait of Hormuz.

Since the two-week ceasefire started, US President Donald Trump has voiced displeasure at Iran's handling of the strategic strait, which was meant to be reopened. Tehran has in turn reacted angrily to Israeli attacks in Lebanon, insisting that it too falls under the agreement.

Trump posted on his Truth Social network on Friday that Iran has "no cards" in the talks "other than a short-term extortion of the World by using International Waterways".

Pakistani Prime Minister Shehbaz Sharif thanked both sides for agreeing to meet, but said the talks will be hard work.

"A temporary ceasefire has been announced, but now an even more difficult stage lies ahead: the stage of achieving a lasting ceasefire, of resolving complicated issues through negotiations," he said in a televised speech.

"This is that stage which, in English, is called the equivalent of 'make or break'."