TEHRAN -- Iran's official news agency IRNA said on Sunday the country has rejected taking part in the second round of the peace talks with the United States.

Iran's absence from the second round of talks "stems from what it called Washington's excessive demands, unrealistic expectations, constant shifts in stance, repeated contradictions, and the ongoing naval blockade, which it considers a breach of the ceasefire," the agency said in a post on its English account on social media platform X.

In another report published in Farsi, IRNA said reports released about the second round of peace talks between Tehran and Washington in Islamabad are "not true."

It described the reports released by the United States as part of a "media game and in line with the blame game" to pressure Iran, stressing that the US "excessive, illogical and unrealistic demands, frequent changing of positions, constant contradictory remarks, continuation of the so-called naval blockade" have so far prevented the negotiations' progress.

IRNA added under the present circumstances, there is "no bright prospect" for fruitful negotiations.

On Feb 28, Israel and the United States launched joint attacks on Tehran and several other Iranian cities, killing Iran's then Supreme Leader Ali Khamenei, along with senior military commanders and civilians. Iran responded by launching waves of missile and drone strikes targeting Israel and US bases and assets in the Middle East, and exercising tight control over the Strait of Hormuz.

A ceasefire was achieved between the warring parties on April 8, which was followed by lengthy talks between the Iranian and US delegations in Pakistan's capital Islamabad on April 11 and 12. After the peace negotiations in Islamabad collapsed, the United States imposed its own blockade on the waterway.

The Iranian and US delegations were reportedly expected to hold another round of peace talks in Pakistan soon.