US President Joe Biden held talks on Thursday with Israeli leaders in Jerusalem — and Iran was high on the agenda.   

Both sides declared a "united stand" on Tehran and signed a joint agreement pledging to prevent Iran from acquiring a nuclear weapon, officials said.

"We will make sure Israel will be able to defend itself by itself," Biden said during a press conference with Israeli Prime Minister  Yair Lapid.

The United States is "prepared to use all elements of national power" to prevent Iran from obtaining nuclear weapons, according to a joint statement.

A senior Biden administration official told reporters in a conference call before the statement was released that the deal will further bolster the two nations' already close security partnership.

"This declaration is pretty significant, and it includes a commitment to never allow Iran to acquire a nuclear weapon and to address Iran's destabilizing activities, particularly threats to Israel," the official said.

An Israeli official called the document "a living testimony to the unique quality, health, scope, depth and intimacy of the US-Israel relationship," the AFP news agency reported. 

"It takes a very clear and united stand against Iran, its nuclear program and its aggression across the region," the official, who asked not to be named, added.

In an interview taped in Washington before he left for the Middle East, Biden told Israel's Channel 12 that he would be willing to use force against Iran as a "last resort" to stop Tehran from acquiring nuclear weapons.

"The only thing worse than the Iran that exists now is an Iran with nuclear weapons," he said.

Iran's nuclear threat

Israel was staunchly opposed to a nuclear deal Tehran signed with world powers to put the breaks on its nuclear program in 2015.

The agreement sharply limited Iran's nuclear program, while forcing Tehran to strict international verification in exchange for the lifting of international sanctions.

But Israel argued that the restrictions on Iran's nuclear enrichment were not permanent and that the accord failed to address the nation's missile program or military activities in the region.

Biden's predecessor, Donald Trump, withdrew the US from the deal and slapped unilateral sanctions on Tehran.

But Biden, who called Trump's move a "gigantic mistake," has tried to resurrect the deal, but those efforts appear to be faltering as Iran continues to expand its nuclear program, according to reports by the International Atomic Energy Agency.

Following a meeting Thursday with Lapid, Biden said, "We're waiting for their response. When that will come, I'm not certain. But we are not going to wait forever."

For its part, Israel would prefer strict sanctions in hopes that they would compel Tehran to agree to a more sweeping accord.

Who will Biden meet on Thursday?

This is the second day of Biden's Middle East trip, the president's first visit to the region since he assumed office.

Biden begins the day by meeting Lapid, who became head of an interim government earlier this month after the previous coalition collapsed.

Biden will later appear at a joint news conference with Lapid.

Both leaders will also attend a virtual summit with India and the United Arab Emirates, part of a grouping known as the I2U2.

Biden is also expected to meet opposition leader and former Prime Minister Benjamin Netanyahu, whose conservative Likud party is projected to win the most seats in the next elections slated for November.

Furthermore, Biden will receive Israel's top civilian honor, the presidential medal of honor, from President Isaac Herzog on Thursday.

Biden to meet Palestinian President Mahmoud Abbas

Biden will meet Palestinian President Mahmoud Abbas on Friday in the occupied West Bank, and will likely pledge US financial support to the territory.

Later on Friday, Biden will fly from Israel directly to Jeddah, Saudi Arabia, for talks with Saudi officials.

Ahead of Biden's visit, Saudi Arabia's civil aviation authority said it was lifting restrictions on all "all carriers" using its airspace, a possible goodwill gesture towards Israel. Biden praised the Saudi move, according to the White House.

While in Saudi Arabia, Biden will also attend a summit of Gulf allies.

sri/sms, wd (Reuters, AP, AFP)