WASHINGTON, Dec 9 (Reuters) - (This Dec. 9 story has been corrected to fix the date of Blinken's statement to last year, instead of November, in the eighth paragraph)President Joe Biden next week will announce U.S. support for the African Union's admission to the G20 group of the world's largest economies as a permanent member, a White House official said on Friday.Biden will make the announcement during the U.S.-Africa Leaders Summit in Washington next week, White House adviser Judd Devermont said, when Biden will meet presidents of African countries.The United States released a new strategy document for sub-Saharan Africa in August, stressing the region's importance, the threats posed by China and Russia, and vowing to extend defense cooperation with like-minded African countries.Last year, U.S. Secretary of State Antony Blinken said Washington would have to do things differently to help Africa with its infrastructure needs and it was time to stop treating the continent as a subject of geopolitics and rather as a major player on its own.But Biden has struck a different tone from former President Donald Trump, who disparaged some African nations and barred travel from six of them."