The United States has destroyed six Iranian boats and shot down missiles and drones fired at U.S. Navy and commercial vessels by Tehran's forces, a top U.S. admiral said Monday.

The UAE said Monday that its air defenses were dealing with Iranian missile and drone attacks, after saying that it previously intercepted three missiles over its territorial waters earlier in the day.

A drone strike meanwhile caused a fire at an energy installation in the emirate of Fujairah, authorities said.

President Joseph Aoun said on Monday that a security deal and an end to Israeli attacks were needed before any meeting with Israeli Prime Minister Benjamin Netanyahu, sought by Washington.

Aoun's office said in a statement that the president "reiterated his view that the timing is not appropriate now for a meeting" with Netanyahu, and quoted Aoun as saying: "We must first reach a security agreement and stop the Israeli attacks on us before we raise the issue of a meeting between us."

Israeli police on Monday warned people not to defy the cancelation of a major pilgrimage near the border with Lebanon, scrapped because of hostilities with Hezbollah, while local media reported thousands had gathered at the site.

Fighting between Israeli forces and Hezbollah is ongoing in southern Lebanon despite a ceasefire in effect since mid-April.

Hezbollah said its forces clashed with Israeli soldiers on Monday in south Lebanon near the border where its troops are still operating, despite a ceasefire since April 17.

Hezbollah in a statement said that after Israeli troops attempted to advance near the town of Deir Seryan -- which is inside the Israeli-declared "yellow line" where Lebanese residents have been told not to return -- its fighters "opened fire on the enemy force and engaged in heavy clashes with them".

A Hezbollah lawmaker urged Lebanese authorities on Monday to declare the U.S. ambassador "persona non grata" after the envoy suggested those who had offended Maronite Patriarch Beshara al-Rahi should leave the country.

The controversy erupted on Saturday after a video published by Lebanese television channel LBCI caricatured Hezbollah leaders and fighters as characters from the "Angry Birds" mobile phone games, triggering sectarian-tinged debate.

Iranian media said Monday that a U.S. navy frigate was targeted by two missiles in the Strait of Hormuz, after President Donald Trump said US forces would begin guiding ships through the waterway.

"The frigate, which was sailing on Monday in the Strait of Hormuz, in violation of navigation and maritime safety rules near (the port of) Jask, was targeted by a missile attack after ignoring a warning from the Iranian navy," the Fars news agency said, without citing a source.

A Russian missile attack on an east Ukrainian town killed four people and wounded 16, authorities said Monday.

The governor of Ukraine's eastern Kharkiv region, Oleg Synegubov, said the strike targeted the town of Merefa, adding: "The victims are men aged 50 and 63, and women aged 41 and 52."

Israeli strikes on southern Lebanon killed at least one person and wounded four rescuers on Sunday, the Lebanese health ministry said, as Israel maintained its attacks on the country despite a fragile truce.

In separate statements, the ministry said a strike on Arabsalim killed at least one person and wounded three, including a child, and another strike on Srifa wounded five people including four rescuers from the Hezbollah-affiliated Islamic Health Committee, as the strike hit near one of their centers.

Iran's military said Monday that U.S. forces would be attacked if they entered the Strait of Hormuz, after U.S. President Donald Trump announced Washington would begin escorting ships through the blocked waterway.

"We warn that any foreign armed force -- especially the aggressive U.S. military -- if they intend to approach or enter the Strait of Hormuz, will be targeted and attacked," said Major General Ali Abdollahi of the Iranian military's central command, in a statement carried by state broadcaster IRIB.