President Joe Biden on Tuesday announced new financial sanctions on Russia, cutting off the country from some Western financing after Russian troops were authorized to enter eastern Ukraine on Monday, a move Biden called the “beginning of a Russian invasion.”

"Russia has now undeniably moved against Ukraine," the president said in the White House's East Room.

Biden has promised “severe” sanctions in coordination with allies if Russia entered Ukraine, and he announced the "first tranche" would be imposed on two of Russia’s banks and its government debt.

“That means we’ve cut off Russia’s government from Western finance,” the president said. “It can no longer raise money from the West and cannot trade in its new debt on our markets or European markets either.”

But these are initial penalties, he added, and more sanctions on Russian elites and their families are coming soon.

“This is the beginning of a Russian invasion of Ukraine," the president said. "I'm going to begin to impose sanctions in response far beyond the steps we and our allies and partners implemented in 2014. And if Russia goes further with this invasion, we stand prepared to go further."

"We’ll continue to escalate sanctions if Russia escalates," Biden said.

A senior administration official on Tuesday said that the U.S. was being tactical by only issuing one phase of financial sanctions on Russia, and they said the goal was to deter a full-scale invasion into Ukraine and its major cities.

“This is the beginning of an invasion, and this is the beginning of our response,” the official said.

“The Kremlin can no longer raise money from the U.S. and Europe, and its new debt can no longer trade in U.S. or European markets,” the official added, calling the sanctions “severe.”

But the official also said there are additional penalties in the works, including sanctions on Russian oligarchs and their families.

They later added: “No one should think that our ultimate goal is to max out on sanctions. They're not an end of themselves. Sanctions are meant to serve a higher purpose, which is to deter and prevent. So we want to prevent a large-scale invasion in Ukraine."

The senior administration official also said the U.S. was preparing export controls in case Russia made additional moves into Ukraine, and they pointed to the U.S. troop fortification in eastern Europe.

They also noted the United States’ role in Germany halting the construction of Nord Stream 2, a key natural gas pipeline from Russia. Many critics of the controversial pipeline said it would make Europe too reliant on Russian energy supplies.

Biden also announced that U.S. troops stationed in Europe will adjust their positions to back up the United States’ Baltic allies: Estonia, Latvia and Lithuania. But the moves are only defensive, he emphasized.

“Let me be clear: These are totally defensive moves on our part. We have no intention of fighting Russia,” the president said. “We want to send an unmistakable message that the United States, together with our allies, will defend every inch of NATO territory.”

He pointed to Putin as the sole aggressor in the Ukraine crisis, and he said the U.S. believes Putin is prepared to go further, partly because they have massed medical supplies and blood on their border.

“You don't need blood unless you plan on starting a war,” the president said, adding that Russia has no justification for an attack.

President Biden emphasized that NATO allies remain united and open to diplomacy, though the outlook is grim.

“We're clear eyed about the challenges we're facing. Nonetheless, there's still time to avert the worst-case scenario that will bring untold suffering to millions of people if they move as suggested,” he said. “We're going to judge Russia by its actions, not its words. And whatever Russia does next, we're ready to respond with unity, clarity and conviction.”

"None of should be fooled," Biden said. "None of us will be fooled. There is no justification for the Russian assault on Ukraine."