The long-time Israeli leader will speak to a joint meeting of the Senate and House of Representatives at 2 p.m. EDT (1900 GMT), passing British wartime leader Winston Churchill, who made such addresses three times.

Netanyahu's speech is expected to focus on coordinating the Israeli and U.S. response to the volatile situation in the Middle East, where there is a growing danger of the Gaza war spilling over into a wider regional conflict.

He is also expected to use his speech to call for stronger action against Iran, which supports Hamas and Lebanon’s Hezbollah fighters and has drawn increased U.S. condemnation over its recent nuclear advances.

Though Netanyahu's visit was orchestrated by Congress' Republican leaders, it is likely to be less confrontational than in 2015, when Republicans sidestepped then-President Barack Obama and invited Netanyahu's to Congress to criticize the Democrat's Iran policy.

This time, Netanyahu will seek to bolster his traditional links to Republicans but also look to ease tensions with Biden, whom he will rely on for the remaining six months in the president's term.

He must also reach out to Vice President Kamala Harris, who has at times been more forward-leaning than her boss in criticizing Israel for heavy Palestinian civilian casualties in Gaza.

Activists have promised mass protests, and the Capitol building was surrounded by high fencing and additional police. Dozens of Washington streets were also due to be closed on Wednesday.

PREOCCUPIED WASHINGTON

Netanyahu's speech comes as Washington is largely preoccupied with the fallout from Biden’s announcement on Sunday that he was ending his re-election bid and endorsing Harris for the Democratic presidential nomination.

Dozens of Democrats plan to skip the speech, many expressing dismay over Israel's war in the Palestinian enclave and saying they do not want to help Netanyahu offset declining domestic poll numbers. The Palestinian death toll from the offensive has exceeded 39,000, Gaza health officials said.

"For him, this is all about shoring up his support back home, which is one of the reasons I don't want to attend," Senator Chris Van Hollen told reporters. "I don't want to be part of a political prop in this act of deception. He is not the great guardian of the U.S.-Israel relationship."

The Democrats planning to stay away also included Senators Dick Durbin, the chamber's number two Democrat, Tim Kaine, Jeff Merkley and Brian Schatz, all members of the Senate Foreign Relations Committee, as well as Patty Murray, who chairs Senate Appropriations.

In the House, those staying away included progressives like Representatives Rashida Tlaib and Alexandra Ocasio-Cortez, as well as Ami Bera, a senior member of the Foreign Affairs Committee, and Adam Smith, the top Democrat on Armed Services.

Smith said he never attends joint meetings but also described himself on Tuesday as "very, very opposed to what Prime Minister Netanyahu is doing in Israel."

Murray normally would have presided, as the senior Senate Democrat, because Harris will not attend. Democratic Senator Ben Cardin, who leads the foreign relations committee, will replace her.

Some Republicans criticized Harris for traveling outside Washington instead of going to the speech. She will meet with Netanyahu separately.

But she was not the only candidate staying away. Republican Senator J.D. Vance, running for vice president on the ticket with former President Donald Trump, will be away "as he has duties to fulfill as the Republican nominee for Vice President," Trump campaign senior adviser Jason Miller said in a statement.

Netanyahu was to travel to Florida to meet with Trump later this week. The meeting will be their first since the end of Trump's presidency, during which the two forged close ties.