U.S. Secretary of State Marco Rubio says a purported offer from Iran to reopen the Strait of Hormuz under strict conditions is not acceptable to the United States or others.

U.S. President Donald Trump will hold talks on the Iran war on Monday with his top security advisors, US media reported, as negotiations between the rival parties seemed to reach an impasse.

Russian President Vladimir Putin told Iran's top diplomat that Moscow would do everything it could to help secure peace in the Middle East, during a meeting in Saint Petersburg on Monday.

Iran's foreign minister on Monday said the Islamic republic was "stable, solid" during a meeting in Russia with President Vladimir Putin, according to Russian state TV.

Iran is offering to end its chokehold on the Strait of Hormuz without addressing its nuclear program, two regional officials with knowledge of the proposal said Monday, as the country's foreign minister made a visit to Russia he said was an opportunity to consult with Moscow regarding the war against Israel and the United States.

Iran also wants the U.S. to end its blockade of the country as part of its proposal, said the two officials, who spoke on condition of anonymity to discuss the closed-door negotiations.

Iranian Foreign Minister Abbas Araghchi on Monday blamed the United States for the failure of peace talks in Pakistan, after arriving in Russia for a meeting with President Vladimir Putin.

"The U.S. approaches caused the previous round of negotiations, despite progress, to fail to reach its goals because of the excessive demands," Araghchi was quoted as saying by Iranian state media.

Iran's foreign minister was due to return to Pakistan on Sunday as international mediators try to keep peace talks on track despite U.S. President Donald Trump calling off his envoys' planned trip.

U.S. President Donald Trump said Saturday a shooting at the White House Correspondents' Association dinner would not deter him from the Iran war, although he believed the incident was unlikely linked to the conflict.

International efforts to mediate between the United States and Iran were in the balance on Sunday, after President Donald Trump canceled his envoys' planned trip to Pakistan for talks.

U.S. President Donald Trump announced he had cancelled his envoys' planned trip to Pakistan for peace talks with Iran on Saturday, but said that did not mean an immediate resumption of the U.S.-Israeli war against the Islamic republic.