A Russian court on Tuesday dismissed WNBA basketball star Brittney Griner's appeal against a nine-year sentence for possessing and smuggling vape cartridges containing cannabis oil, paving the way for her to be sent to a penal colony, in a court case that Washington has called a "sham."

U.S. President Joe Biden, whose administration in late July had proposed a deal for a prisoner swap with Russia to secure the release of Griner and former U.S. marine Paul Whelan, said he will not let up efforts to bring them home.

"We're in constant contact with Russian authorities to get Brittney and others out. So far we've not been meeting with much positive response but we're not stopping," he said.