Dominic Raab has said Britain does not accept the results of the “fraudulent” election in Belarus.
The UK’s foreign secretary has called for an urgent investigation into the ballot’s “serious flaws”.
Mr Raab also condemned acts of violence by the Belarusian authorities to suppress peaceful protests following the re-election of President Alexander Lukashenko.
He said the government will work with international partners to sanction those responsible and hold the country’s authorities to account.
“The world has watched with horror at the violence used by the Belarusian authorities to suppress the peaceful protests that followed this fraudulent presidential election,” Mr Raab tweeted on Monday.
“The UK does not accept the results.”