Republican presidential frontrunner Donald Trump expressed his support for Israel's war in Gaza Tuesday, in his most explicit comments yet on the fighting, as international pressure grows on the United States to rein in its ally.

"Yes," Trump responded, when asked during an interview on Fox News if he was "in Israel's camp."

The interviewer then asked if the former president was "on board" with the way Israel was executing its offensive in Gaza.

"You've got to finish the problem," Trump responded.

President Joe Biden, whom Trump is set to challenge for the White House in November, has come under increasing fire both internationally and from his own Democratic base over his backing for Israel as the death toll in Gaza soars and the specter of famine looms.

The fighting began with an attack by Palestinian militant group Hamas on southern Israel on October 7, resulting in about 1,160 deaths, most of them civilians, according to an AFP tally based on official Israeli figures.

Israel's retaliatory offensive in the Gaza Strip has killed 30,534 people, mostly women and children, according to the health ministry in the Hamas-ruled territory.

US protest movements have urged voters to punish Biden at the polls over his support for Israel. More than 100,000 people in Michigan voted "uncommitted" rather than cast their ballot for him in the US swing state's Democratic primary last week.

As conditions deteriorate, Israel is facing an increasingly sharp rebuke from its top ally the United States.

Vice President Kamala Harris expressed "deep concern about the humanitarian conditions in Gaza" during talks in Washington on Monday with Israeli war cabinet member Benny Gantz.