Senior US and Iranian officials met on Saturday in Islamabad with Pakistani intermediaries as Tehran laid down its red lines -  including the Strait of Hormuz issue, the release of Iran's blocked assets and payment of war reparations - ​that it said Washington must accept before face-to-face talks could take place to end their six-week-old war, said media reports.

Meanwhile, President Donald Trump said the US is starting the process of 'clearing out' the Strait of Hormuz, the vital waterway that has been central to negotiations. It was not initially clear what that would entail, reported CNN.

“We’re now starting the process of clearing out the Strait of Hormuz as a favor to Countries all over the World, including China, Japan, South Korea, France, Germany, and many others. Incredibly, they don’t have the Courage or Will to do this work themselves,” Trump posted on Truth Social shortly after arriving at his golf club in Virginia today.

It is unclear what exactly clearing out the strait entails. CNN has reached out to US Central Command for information.

He continued: “Very interestingly, however, empty Oil carrying ships from many Nations are all heading to the United States of America to LOAD UP with Oil.”

The critical oil thoroughfare traffics approximately 20% of the world’s total oil supply. Reopening the strait was a key provision in the ceasefire agreement, though few ships have traversed the waterway since it went into effect days ago.

Pakistani Prime Minister Shehbaz Sharif on Saturday met US Vice President JD Vance, special envoy Steve Witkoff ‌and President Donald Trump's son-in-law Jared Kushner, the White House and Sharif's office said.

Hours earlier, the Iranian delegation led by Parliamentary Speaker Mohammad Baqer Qalibaf and Foreign Minister Abbas Araqchi also met with Sharif to determine the timing and manner of possible negotiations, according to local media.

Iranian state TV said Tehran's delegation had set out its red lines to Sharif, adding that these concerned the Strait of Hormuz, the release of Iran's blocked assets, the payment of war reparations, and a ceasefire to be enforced across the region.

"We will ​negotiate with our finger on the trigger," Iranian government spokesperson Fatemeh Mohajerani said on state TV. "While we are open to talks, we are also fully aware of the lack of trust; therefore, Iran's diplomatic team is ​entering this process with maximum caution."

Earlier, a senior Iranian source told Reuters the US had agreed to release frozen assets held in Qatar and other foreign banks, but a US official ⁠swiftly denied the claim.

The Iranian source welcomed the alleged move as a sign of "seriousness" in the talks, in which Washington is pressing Tehran to reopen the Strait of Hormuz to international shipping.

Qatar's Foreign Ministry did not immediately respond ​to a request for comment on the assertion about frozen assets.

Iran is also demanding a ceasefire in Lebanon, where Israeli attacks on Iran-backed Hezbollah militants have killed nearly 2,000 people since the start of fighting in March.

Israel and the US have ​said the Lebanon campaign is not part of the Iran-US ceasefire.

As direct talks between US and Iran take place in Islamabad with Pakistan, Israel says it is continuing strikes on targets in Lebanon, reported BBC.

Israel Defense Forces (IDF) says it has struck more than 200 Hezbollah targets in Lebanon in the past 24 hours.

In a statement, it says its air force is carrying out further attacks and supporting ground forces operating in southern Lebanon. The IDF also says it is targeting launchers to prevent attacks on Israel.

Trump posted on social media on Friday that the only reason the Iranians were alive was to negotiate a deal.

"The Iranians don't seem to realize they have no cards, other than a short term extortion of the World by using International Waterways. The only reason they are alive today is to negotiate!" he said.

Vance, speaking as he headed to Pakistan, said he expected a positive outcome but added: "If they're going to try to play us, then they're going to find the negotiating team ​is not that receptive."