Iranian Foreign Minister Seyed Abbas Araghchi conveyed Tehran's "red lines" to the United States through Pakistan during his recent visit, the semi-official Fars news agency reported on Sunday.

The report said that the "red lines," relayed to the US side in the form of written messages, pertain to Tehran's nuclear program and the Strait of Hormuz.

The exchange of messages was not related to negotiations but rather part of an initiative by Iran to clarify the situation in the region and explicitly announce its red lines, said the report.

Araghchi on Sunday traveled to the Pakistani capital Islamabad for the second visit since Friday, following a brief stop in Oman.

On Feb. 28, Israel and the United States launched joint attacks on Tehran and other Iranian cities, killing Iran's then-Supreme Leader Ali Khamenei, senior commanders, and civilians. Iran responded with waves of missile and drone strikes targeting Israel and U.S. bases in the Middle East, and tightened control over the Strait of Hormuz, blocking passage by vessels belonging to or affiliated with Israel and the United States.

An April 8 ceasefire was followed by Iran-US talks in Islamabad on April 11 and 12. After the negotiations collapsed, the United States imposed a blockade on the Strait of Hormuz, preventing ships to and from Iranian ports from transiting.