U.S. President Joe Biden asked Americans to spend billions more dollars to help Israel fight Hamas while Israel's defense chief told his troops to be ready to go into the Gaza Strip to destroy the Palestinian militant group.

In a televised White House speech late on Thursday that also addressed Ukraine's effort to repel Russia's invasion, Biden said Hamas sought to "annihilate" Israel's democracy.

The president also stressed the urgency of getting relief to Palestinian civilians in Gaza who lack food, water and medicine.