Washington, United States - US President Joe Biden warned Israeli Prime Minister Benjamin Netanyahu on Monday that a ground offensive in Rafah would be a "mistake," as they spoke for the first time in a month amid growing tensions over the war in Gaza.

In a sign of growing US pressure as the death toll in Gaza soars and the humanitarian situation worsens, Netanyahu agreed to Biden's request to send a team of top Israeli security officials to Washington to discuss its Rafah plans.

But Netanyahu said he had insisted to Biden on achieving Israel's war aim of eliminating Hamas -- the Palestinian militant group behind the October 7 attacks on Israel -- underscoring US difficulties in influencing its key ally.

The two leaders last spoke on February 15 and Biden has shown increasing impatience with Netanyahu, fearing that domestic opposition to the war could hurt his reelection chances in November.

"The president explained why he is so deeply concerned about the prospect of Israel conducting major military operations in Rafah," White House National Security Advisor Jake Sullivan told reporters Monday.

"A major ground operation there would be a mistake -- it would lead to more innocent civilian deaths, worsen the already dire humanitarian crisis, deepen the anarchy in Gaza, and further isolate Israel internationally."

Roughly 1.5 million people are sheltering in Rafah, most of them displaced by Gaza's war.

Biden had asked Netanyahu during the call to dispatch a delegation to the United States to "hear US concerns" about its Rafah plan and "lay out an alternative approach" involving targeted attacks on Hamas leaders.

Netanyahu "obviously has his own point of view on a Rafah operation" but had agreed to send the team of military, intelligence and aid officials in the coming days, Sullivan added.

Sullivan meanwhile confirmed that Israel had killed Hamas's third-in-command Marwan Issa in an operation last week. Israel previously said he had been targeted in a Gaza airstrike but did not confirm his death.

- 'Threat to Israel' -

Netanyahu said in a statement after the Biden call that he had reiterated "Israel's commitment to achieving all of the war's objectives."

The Israeli premier cited the objectives as eliminating Hamas, releasing all hostages held by the group and "ensuring that Gaza will never present a threat to Israel."

He also pointed to the provision of "essential humanitarian aid that helps achieve these aims."

The call was the first since Biden -- who has continued to supply Israel with billions of dollars in military assistance -- was caught on a hot mic saying he would have a "come-to-Jesus meeting" with Netanyahu.

As his frustrations with Netanyahu escalated, Biden pointedly praised a "good speech" last week by Democratic Senate Majority Leader Chuck Schumer calling for new elections in Israel.

With the UN warning of imminent famine in Gaza, Biden earlier this month ordered the US military to start airdrops of food into the enclave and has sent a temporary US port there to speed up delivery of maritime aid.

Asked about reports that some of Biden and Netanyahu's conversations have been angry and finished with the US president hanging up, Sullivan described Monday's call as "businesslike" and said it "did not end abruptly."

Explaining why the two leaders had not spoken for 32 days, Sullivan said Biden reserves his calls for Netanyahu for "when he believes there is a key strategic moment."

Israel began relentless bombardment in Gaza, alongside a ground offensive, after Hamas's unprecedented October 7 attack, which left about 1,160 dead in Israel, mostly civilians, according to an AFP tally of official figures.

The militants also seized hostages, around 130 of whom Israel believes remain in Gaza, including 33 presumed dead.

Nearly 32,000 people have been killed in Gaza since the war began, most of them women and children, according to the health ministry in the Hamas-run territory.