Biden will announce the news in his State of the Union address, a source said.
Russian forces are continuing their attempted push through Ukraine from multiple directions, while Ukrainians, led by President Volodymr Zelenskyy, are putting up "stiff resistance," according to U.S. officials.
The attack began Feb. 24 as Russian President Vladimir Putin announced a "special military operation."
Russians moving from Belarus towards Ukraine's capital, Kyiv, don't appear to have advanced closer towards the city since coming within about 20 miles, although smaller advanced groups have been fighting gun battles with Ukrainian forces inside the capital since at least Friday.
Russia has been met by sanctions from the U.S., Canada and countries throughout Europe, targeting Russia's economy and Putin himself.
A senior U.S. official told ABC News they've heard a Russian soldier on a radio call saying, “We don’t know who to shoot -- they all look like us.”
The official also said some Russian forces are disoriented, realizing the battles against Ukrainians are harder than they thought.
-ABC News' Martha Raddatz
German Chancellor Olaf Scholz has announced that Germany is dropping its historic position of not providing lethal military aid to conflict zones, saying Russia's "invasion marks a turning point."
Germany will provide 1,000 anti-tank weapons and 500 Stinger missiles, he said.
The Netherlands is also announcing new lethal aid, according to its Defense Ministry.
The $350 million military aid package from the U.S. will include “anti-armor, small arms and various munitions, body armor, and related equipment in support of Ukraine’s front-line defenders facing down Russia’s unprovoked attack," Pentagon spokesman John Kirby said. The U.S. package also includes portable surface-to-air missiles (MANPADS) in the Pentagon's inventory, a U.S. official told ABC News.
-ABC News' Conor Finnegan
At a border crossing near Zosin, Poland -- due west of Kyiv -- Ukrainians are waiting for 40 hours to cross into Poland in a nearly 10-mile backlog, said Chris Meltzer of the United Nations High Commissioner for Refugees.
Meltzer said one woman with her two children told him it took her 12 hours to get out of Kyiv and then they spent another 38 hours waiting in their car without heat or a bathroom.
He said the biggest needs are blankets, clothes and accommodations.
Meltzer said, once they cross, most Ukrainians are staying in the border region because they want to return home as soon as possible.
-ABC News' Cindy Smith
Ukraine’s president Volodymyr Zelenskyy said Saturday Western countries have agreed to disconnect Russia from the Society for Worldwide Interbank Financial Telecommunication (SWIFT) banking network.
"For Russia it will mean being cut off [from] normal financial civilization. This is a big diplomatic victory," he said. "Russia will suffer billions upon billions of financial losses -- their price for invasion."
Ukraine’s foreign minister said earlier that technical preparations have begun for disconnecting Russia from SWIFT and that the last holdouts, Germany and Hungary, have signaled they're no longer opposed.
Zelenskyy also said Turkey’s president has agreed to close the straits into the Black Sea to Russia.
Zelenskyy continued, "You know, it was a beautiful sunny day in Kyiv today that occupiers tried to ruin. But today is also the first day in the life of the baby girl born in the shelter in Kyiv metro station."
"We fight back strongly … and we will do our best to liberate our country," he said. "When babies come into this world even under shelling and fire, then the enemy has no chance in this war.”
-ABC News' Patrick Reevell
