Joe Biden
Joe Biden Reuters

Pennsylvania has certified Joe Biden's victory in the state, Governor Tom Wolf announced Tuesday. three weeks after the 2020 US presidential election.

“As required by federal law, I’ve signed the Certificate of Ascertainment for the slate of electors for Joe Biden and Kamala Harris," Wolf, a Democrat, wrote on Twitter.

Biden will pick up Pennsylvania's 20 electoral votes as a result.

Outgoing President Donald Trump has sought to challenge the results in Pennsylvania and several other states, alleging that massive voter fraud is what led to Biden's victory.