The appeal comes after Biden flew to Tel Aviv on Wednesday pledging his support for Israel in the wake of the sprawling attack carried out by Hamas militants this month.
In an address Thursday, only his second from the Oval Office, Biden said that supporting Ukraine and Israel is a matter of US national security when the world is at an inflection point.
“I know these conflicts can seem far away, " he said. "It’s natural to ask why does this matter to America? So let me share with you making Israel and Ukraine succeed is vital for America’s national security.
"History has taught us that when terrorists don’t pay a price for their terror, when dictators don’t pay a price for their aggression, they cause more chaos and death and more destruction. They keep going and the cost of the threats to America and the world keep rising.”
President Biden said Hamas and Russia are both out to "annihilate" democracies.
The president said he is requesting $100 billion from Congress to deliver aid and resources to Ukraine and Israel. The US, Egypt and Israel have all signaled readiness for aid to begin moving into Gaza, following Biden’s high-profile visit this week.
“That’s why tomorrow I’m going to send to Congress an urgent budget request to fund America’s national security needs, to support our critical partners including Israel and Ukraine.
"It’s a smart investmen," he continued, "that’s going to pay dividends for American security for generations, help us keep American troops out of harm’s way, help us build a world that’s safer, more peaceful, more prosperous for our children and grandchildren.”
Presidents traditionally reserve speeches from the solemn setting of the Oval Office for moments of key national significance.
Biden's only previous address from the Oval Office was in June when he hailed a deal with Congress to avert what would have been a catastrophic US debt default.
The Biden administration in August delivered its last supplemental funding request. The proposal requested $24.1 billion to aid Ukraine through the end of the year, but Congress failed to approve it during a process to green-light short-term federal funding. Congress – divided between a Republican-controlled House and a Democrat-dominated Senate -- has been paralyzed for over two weeks without an elected House speaker.
Biden made his speech less than a day after returning from a trip to Israel to show his support after an attack by Hamas militants from the Gaza Strip enclave in between Israel and Egypt.