Iran will not enter a second round of negotiations with the United States unless five preconditions aimed at building trust are met, the semi-official Fars News Agency reported Tuesday, citing an informed source.

The source described the demands as "minimum trust-building guarantees" required before any new talks with Washington could begin. The conditions include ending hostilities on all fronts, particularly in Lebanon; lifting sanctions on Iran; releasing frozen Iranian assets; compensating Iran for war damage; and recognizing Iran's sovereignty over the Strait of Hormuz.

The source said these demands were conveyed to the United States in response to a 14-point US proposal.

According to the report, Iran also informed Pakistan, which is mediating the negotiations, that the continued US naval blockade in the Arabian Sea and Gulf of Oman following the ceasefire had reinforced Tehran's distrust of Washington.

The source said that the conditions are intended solely to establish a minimum level of trust necessary to resume dialogue. Tehran sent its formal response to the latest US draft proposal to the Pakistani mediator on Sunday.

Iranian Foreign Ministry spokesperson Esmaeil Baghaei said on Monday that Tehran's proposal seeks only to secure the Iranian people's "legitimate" rights.

Separately, Ebrahim Rezaei, spokesperson for Iranian parliament's National Security and Foreign Policy Committee, warned on Tuesday Iran might increase its uranium enrichment to 90% if attacked again.

Meanwhile, Mohammad Eslami, director of the Atomic Energy Organization of Iran, stated that nuclear technology and uranium enrichment will not be part of any potential talks with the US.

US President Donald Trump emphasized on Monday that Washington's proposal is centered on preventing Iran from ever acquiring nuclear weapons. He noted that Iran's response did not provide such a commitment. Trump added that the current US-Iran ceasefire remains in place but is "extremely fragile."

The US 14-point proposal, reportedly a one-page memorandum of understanding, includes two core elements: Iran opening the Strait of Hormuz in exchange for the gradual lifting of the US naval blockade, and Iran limiting its nuclear program in return for partial sanctions relief. Following the outbreak of war, Iran had blocked the Strait of Hormuz, triggering major disruptions in the global energy market.

In response to the heightened regional tensions, the British Ministry of Defense announced on Tuesday that the UK would deploy drones, fighter jets and naval vessels to support the multinational escort mission in the Strait of Hormuz. The deployment will include Typhoon fighter jets and the HMS Dragon destroyer. London said the operation will receive an additional £115 million ($155 million) in funding to build capabilities for mine-hunting drones and counter-drone systems. Defense Secretary John Healy stated, "The UK will work with allies to advance this multinational mission."

Earlier this month, French President Emmanuel Macron proposed a France- and UK-led multinational escort operation in the Strait of Hormuz in a phone call with Iranian President Masoud Pezeshkian. On the same day, the French Ministry of Defense announced that the aircraft carrier Charles de Gaulle had transited the Suez Canal toward the southern Red Sea to prepare for the mission.

Amid ongoing tensions between the US and Iran, it's reported that Iran has filed claims with the Iran-US Claims Arbitration Tribunal (IUSCT), accusing Washington of military aggression against Iranian nuclear facilities, economic sanctions and threats of force. The claim, addressing US violations during the so-called "12-Day War" in February and March 2026, has been officially registered with the tribunal.

Iran and the United States agreed to a ceasefire on April 8 after 40 days of conflict that began with US and Israeli strikes on Tehran and other Iranian cities on February 28. Delegations from both countries subsequently held talks in Islamabad on April 11–12 but failed to reach an agreement. Since then, both sides have exchanged several draft proposals through Pakistan as part of ongoing efforts to end the conflict.