Israeli Prime Minister Benjamin Netanyahu is to deliver a landmark speech to the US Congress on Wednesday as he fights off intense pressure to quickly cut a Gaza war ceasefire deal with Hamas.
Netanyahu, Israel's longest-serving premier, will become the first foreign leader to address a joint meeting of the two chambers four times -- pulling ahead of Britain's Winston Churchill on three.
But analysts say the Gaza war since the October 7 Hamas attacks has created worrying tensions between Israel and the United States, its main military and diplomatic backer.
Washington fears a backlash from the mounting civilian toll in the Gaza Strip, while protests in Israel by families of hostages taken by Hamas are also causing headaches for Netanyahu.
Biden and some Israeli ministers say a deal negotiated through Qatar, Egyptian and US mediators is possible. A plan outlined in May proposed a six-week ceasefire when some Israeli hostages would be swapped for Palestinians held in Israeli prisons.
US Secretary of State Antony Blinken said Friday that negotiators were "inside the 10 yard line and driving toward the goal line".
Hamas has accused Netanyahu of seeking to block a deal however and Blinken said he wants to "bring the agreement over the finish line" when Netanyahu is in Washington.
An expected meeting between Netanyahu and US President Joe Biden is still not confirmed.
Israel has intensified its air strikes on Gaza in recent weeks and Netanyahu has insisted that only piling on military pressure can free the hostages and beat Hamas.
"This double pressure is not delaying the deal -- it is advancing it," Netanyahu told troops in Gaza on Thursday.
The October 7 attack on Israel resulted in the deaths of 1,195 people, mostly civilians, according to an AFP tally based on Israeli figures. Hamas militants also seized 251 hostages, 116 of whom are still in Gaza, including 42 the Israeli military says are dead.
Israel's retaliatory campaign has killed at least 38,919 people in Gaza, also mostly civilians, according to data from the health ministry in the Hamas-ruled territory.
Publicly, Biden has voiced strong support for Israel. But he expressed concern over an offensive on the southern city of Rafah in May and for a while suspended deliveries of heavy bombs to Israel. Supplies of 2,000-pound bombs remain embargoed.
"Never before has the atmosphere been so fraught," said Council on Foreign Relations Middle East specialist Steven Cook.
"There is clearly tension in the relationship, especially between the White House and the Israeli prime minister," Cook said in a commentary.
While US Republicans pressed to invite Netanyahu to address Congress, he has lost support among Democrats.
One Jewish senator, Democrat Brian Schatz of Hawaii, announced he would boycott Wednesday's speech, saying he would not listen to "political rhetoric that will do nothing to bring peace in the region".
Netanyahu said after being invited to Congress again that he would "present the truth about our just war against those who seek to destroy us".
Cook said that Netanyahu has two aims for his Washington trip.
First, to show that he has not "undermined" Israel's relations with the United States.
Netanyahu also "will endeavour to shift the conversation away from the conflict in Gaza toward the threat that Iran and its proxies pose" to Israel and the United States, Cook added.
Much attention will be focused on whether Netanyahu meets with Donald Trump or a figure close to the Republican presidential candidate.
Despite the tensions, the United States has defended Israeli interests while taking a key role in mediation efforts, and the military relationship remains strong, according to officials.
Washington's support could prove crucial as Israel faces increasing international criticism over the growing humanitarian toll from nearly 300 days of war.
The International Criminal Court's prosecutor in May asked judges to issue arrest warrants for Netanyahu and Israeli Defence Minister Yoav Gallant. Warrants for three Hamas leaders have also been requested.
The Republican majority in the House of Representatives has called for sanctions against the ICC.
The International Court of Justice found Israel's occupation of Palestinian territories illegal on July 19 and in February called for the country to prevent any acts of genocide in its Gaza offensive.
