In response to the Russian offensive in northeast Ukraine, the United States and some other countries have allowed Kyiv to use Western-donated weapons to strike inside Russian territory.

"They're authorized to be used in proximity to the border when they're being used on the other side of the border to attack specific targets in Ukraine," Biden told ABC News in interview remarks released Thursday.

"We're not authorizing strikes 200 miles into Russia and we're not authorizing strikes on Moscow, on the Kremlin."

US officials said last week that Washington had partially lifted its restrictions to enable Ukraine to defend its eastern Kharkiv region, which borders Russia.

The change in the US stance was attributed by officials to Russia's daily pounding of Kharkiv, Ukraine's second biggest city.

Germany also said it had given Ukraine permission to fire German-delivered weapons at targets in Russia.

Biden said the US-supplied weapons were for striking "just across the border, (from) where they're receiving significant fire from conventional weapons used by the Russians to go into Ukraine to kill Ukrainians."

The president was speaking in France where he is attending events marking the 80th anniversary of D-Day.