Iran on Monday fired "warning shots" at two ships attempting to cross the Strait of Hormuz, state television reported, as Tehran and Washington battle for control of the strategic waterway.

The European Union on Monday imposed sanctions on Russian military intelligence officers, hackers and private companies, denouncing what it called a yearslong cyberespionage campaign to undermine the bloc.

The move targeted nine people and four entities accused of links to an online spying network that the EU said has targeted governments and carried out sabotage operations against critical infrastructure like heating and power plants since 2010.

Ukrainian President Volodymyr Zelensky was due in Paris on Monday for talks with two dozen European leaders helping Kyiv fight Russia's invasion, with the war now in its fifth year.

European foreign ministers were also meeting separately in Brussels where they were expected to discuss Ukraine's needs and Russia's threats to the continent.

Prominent U.S. Senator Lindsey Graham, a key ally of President Donald Trump, died on Saturday aged 71 following a "brief and sudden illness," his office said.

Graham, known for his foreign policy work, was a staunch supporter of the Iran war and in recent years urged both Trump and the Biden administrations to back Kyiv's fight against Russia's invasion.

Tehran announced it was closing the Strait of Hormuz on Sunday and launched missiles and drones at its Gulf neighbours, in retaliation for new U.S. strikes following an attack by Iranian forces on a merchant vessel that was abandoned in flames by its crew.

Qatari officials are participating in talks between Iran and Oman in Muscat over the strait of Hormuz, a diplomat with knowledge told U.S. news portal Axios on Saturday.

A regional source told Axios that the parties are discussing a potential statement on full opening of the "median lane" in the strait of Hormuz ,which is in international waters, for full and free movement.

Iran warned that it would no longer be bound by a deal with the U.S. aimed at ending the Middle East war if Washington's violations of the agreement continued, state TV reported on Saturday.

Iran's supreme leader on Saturday vowed revenge for the U.S.-Israeli killing of his father and predecessor, hours after President Donald Trump warned against any attempt to assassinate him.

Iran insisted on Saturday it had "kept its word" on a ceasefire with the United States, after President Donald Trump insisted the truce was over but that he had agreed to further negotiations with the Islamic republic.

Prime Minister Shehbaz Sharif of Middle East conflict negotiator Pakistan has urged Iran's president to safeguard the "hard-earned peace" after Tehran and Washington exchanged strikes this week.