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.
The violence against peaceful protesters in Belarus is appalling. The UK does not accept the results of this fraudulent Presidential election & calls for an urgent investigation through @OSCE into its serious flaws & the grisly repression that followed. https://t.co/VPJ4yrTCXZ
— Dominic Raab (@DominicRaab) August 17, 2020
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.”
The statement also said: “We urgently need an independent investigation through the OSCE into the flaws that rendered the election unfair, as well as the grisly repression that followed.”
Mr Lukashenko said on Monday there will be no new presidential election despite calls from the opposition and nationwide anti-government protests.
“You should never expect me to do something under pressure,” he was quoted as saying by the Belta news agency.
“They [new elections] won’t happen.”
He said work is under way on possible changes to the constitution that would redistribute power, Belta reported.
Earlier, Belarusian opposition politician Sviatlana Tsikhanouskaya said she was ready to lead Belarus.
Speaking in a video address from Lithuania, she called for the creation of a legal mechanism to ensure that a new and fair presidential election could take place.
“I am ready to take responsibility and act as a national leader during this period,” she said.
Ms Tsikhanouskaya, 37, said it was essential to make the most of the momentum generated by a week of protests.
The former English teacher has become one of the leading opposition figures against Mr Lukashenko, who is facing the biggest challenge to his 26-year rule of the country amid a wave of mass protests and strikes.
Ms Tsikhanouskaya fled Belarus last week following the election results, claiming she had done so for the safety of her children, however she soon began releasing videos calling for anti-government protests to continue.
On Sunday, Belarusians chanted “Step down!” in the centre of the capital Minsk in one of the biggest protests so far against the strongman leader’s re-election.
Opponents of the president say he rigged the 9 August election to secure a sixth term in power.
He denies this, however, and according to the official central election commission, the long-standing leader won 80% of the vote – a result rejected by the opposition.
Parts of society usually seen as loyal to the president have come out in support of the protesters, including some police, journalists from state media and a sitting ambassador, while workers from large state factories have staged walkouts.
The first high-ranking government official to side with protesters in Belarus said he expects to be sacked after likening state violence against them to the former Soviet Union under Joseph Stalin.
Igor Leshchenya, the Belarusian ambassador to Slovakia, told Sky News he suspects many colleagues share his view but have not gone public for fear of the consequences.
Germany’s president urged the military in Belarus not to use violence against protesters on Monday.
“I urge the Belarusian military not to sin against their own people by using force,” said Frank-Walter Steinmeier.