By Daphne Psaledakis and Arshad Mohammed

WASHINGTON (Reuters) -International Atomic Energy Agency (IAEA) chief Rafael Grossi on Tuesday asked Ukraine and Russia to respect five principles to safeguard Ukraine's Zaporizhzhia nuclear power plant, suggesting he had not secured their agreement to protect the facility.

Grossi, who spoke at the U.N. Security Council, has tried for months to craft an agreement to reduce the risk of a catastrophic nuclear accident from military activity like shelling at Europe's biggest nuclear power plant, which is in southern Ukraine and has been occupied by Russia for more than a year.

His five principles included that there should be no attack on or from the plant and that no heavy weapons such as multiple rocket launchers, artillery systems and munitions, and tanks or military personnel be housed there.

Grossi also called for off-site power to the plant to remain available and secure; for all its essential systems to be protected from attacks or sabotage; and for no actions that undermine these principles.

"The nuclear safety and security situation at the Zaporizhzhia nuclear power plant ... continues to be extremely fragile and dangerous," he said. "Military activities continue in the region and may well increase very considerably in the near future."

While Russia said it would do all it could to protect the power plant, it did not explicitly commit to abide by Grossi's five principles.

"Mr. Grossi's proposals to ensure the security of the Zaporizhzhia nuclear power plant are in line with the measures that we've already been implementing for a long time," Russia's U.N. Ambassador Vassily Nebenzia said.

Western powers accused Russia, whose forces invaded Ukraine in February 2022, of putting Zaporizhzhia at risk, with the United States demanding that Russia remove its weapons and civil and military personnel from the plant.

"It is entirely, entirely within Moscow's control to avert a nuclear catastrophe and to end its war of aggression against Ukraine," said U.S. Ambassador to the United Nations Linda Thomas-Greenfield.

Russia denies that it has military personnel at the power plant and it describes the war, which has killed thousands and reduced cities to rubble, as a "special military operation" to "denazify" Ukraine and protect Russian speakers.

Ukraine calls it an imperialist land grab prompted by its quest for closer relations with the West after a long history of domination by Moscow.

(Reporting By Daphne Psaledakis and Arshad Mohammed; Editing by Grant McCool)