U.S. President Joe Biden said he has approved a new weapons package worth $150 million for Ukraine's fight to counter Russia's invasion.

"I am announcing another package of security assistance that will provide additional artillery munitions, radars, and other equipment to Ukraine," Biden said, while warning that funding was close to running out and urging Congress to authorize more.

According to a senior U.S. official, the package includes 25,000 155mm artillery rounds, counter-artillery radars used for detecting the source of enemy fire, electronic jamming equipment and spare parts.

The artillery munitions appear to be meant for recently supplied US howitzers.

Prior to Friday, the Biden administration had already sent more than $3.4 billion worth of weaponry, ranging from heavy artillery to shoulder-held Stinger anti-aircraft missiles and drones.

Friday's new package means the remaining $250 available from previously authorized funding for Ukraine will have all but run out.

Biden and the rest of the G7 leaders, plus Ukraine's President Volodymyr Zelenskyy, are meeting virtually on Sunday to discuss Western support for the country in its struggle against President Vladimir Putin's invasion.

Last month Biden proposed a $33 billion assistance package for Ukraine, including more than $20 billion in military aid.