The Group of Seven (G7) countries will announce a ban on Russian gold imports, U.S. President Joe Biden said in a tweet on Sunday. Earlier, the British government confirmed that Russian gold would no longer be allowed to enter the UK, Canada, the U.S. and Japan.

"Together, the G7 will announce that we will ban the import of Russian gold, a major export that rakes in tens of billions of dollars for Russia," Biden said as G7 leaders gathered in Germany.

Reuters quoted a senior U.S. administration official saying the ban would be announced on Tuesday.

"Today, the U.S. and the UK are announcing that G7 leaders will ban imports of Russian gold. The official announcement will come on Tuesday," the official said.

Russia is the world's second-largest producer of gold, accounting for 10 percent of the global output, according to the latest data from the World Gold Council. Gold exports are a major source of revenue for the country, worth $15.45 billion last year.

The move would add to a series of widespread sanctions imposed by Western countries on Russia since the Ukraine crisis began on February 24. The sanctions are targeted at crushing the Russian economy, including bans or curbs on oil and gas imports from Russia.

EU agreed earlier this month to cut 90 percent of oil imports from Russia by the end of 2022, cutting off another vital source of funding for Russia.

As missiles struck the Ukrainian capital Kyiv on Sunday, hitting an apartment block and a kindergarten, Ukraine's Foreign Minister Dmytro Kuleba said the G7 must respond with more weapons and tougher sanctions on Russia.

The first session of the G7 summit will focus on the global economy and concerns over the conflict between Russia and Ukraine, which has driven up energy and food prices globally, according to Al Jazeera.