U.S. President Joe Biden announced additional assistance to Ukraine, including the Patriot missile defense system.

At a briefing in Washington following talks with Ukrainian President Volodymyr Zelensky, he said the United States would send Ukraine an additional $1.8 billion aid package that would include the Patriot missile defense system.

"It is going to take some time to complete the necessary training" to operate the system, but said the Patriot battery would be a "critical asset" for Ukraine's defense, Biden said.

The United States is committed to ensuring that Ukraine can "defend itself against Russian aggression," he said.

The president thanked members of Congress for their bipartisan support for Ukraine, including the latest $45 billion add-on package.

He also said the United States Agency for International Development (USAID) will send more than $374 million in humanitarian aid to Ukraine on Wednesday.

"And today, USAID is committing more than $374 million in urgently needed humanitarian assistance for Ukraine. This will help provide food and cash assistance for more than 1.5 million Ukrainian people, as well as access to healthcare, safe drinking water, and help stay warm in the winter to more than – for more than 2.5 million Ukrainians," Biden said.

It is important for Americans and the rest of the world to continue to hear directly from Ukrainian President Zelensky as the war enters its 300th day, he said, adding "the people of Ukraine and Zelensky's leadership has inspired."

"As we've – as we've heard into – and as we head into the new year, it's important for the American people and for the world to hear directly from you, Mr. President, about Ukraine’s fight and the need to continue to stand together through 2023," Biden said.

Biden praised Ukrainians for their "unbreakable determination" and "strong stand against aggression." The U.S. president said it was "particularly meaningful to talk with one another in person – look each other in the eye, because leadership through this terrible crisis has inspired the Ukrainian people – as you have done, Mr. President – and the American people and the entire world," Biden said.

"Thus far, they have not – they've stood alone. You know, and you've had – but you haven’t stood alone. You have had significant, significant help. We've never stand alone – you will never stand alone," he said.