Belarus's long-serving foreign minister has died "suddenly", the country's state news agency has said.
Vladimir Makei, who had been in post since 2012, was 64.
He attended a conference in the Armenian capital, Yerevan, earlier this week, and had been due to meet Russian foreign minister Sergei Lavrov on Monday.
"Foreign minister Vladimir Makei has passed away suddenly," news agency Belta reported, without offering any further details.
Before presidential elections in 2020 led to large anti-government protests in Belarus, Mr Makei had been among those trying to improve Belarus's relations with the West.
He had also criticised Russia.
Once the protests began, however, he said they had been inspired by agents of the West.
And after Russia invaded Ukraine, earlier this year, he claimed the West had provoked the war.
A few days before it began, on 24 February, he promised there would be no attack on Ukraine from the territory of Belarus, before being proved wrong shortly afterwards.
Russian foreign ministry spokeswoman Maria Zakharova said her country was "shocked" to hear of Mr Makei's death.
Belarussian President Alexander Lukashenko, who retained power despite the protests in 2020, has also expressed his condolences.
But exiled opposition leader, Sviatlana Tsikhanouskaya, said: "In 2020, Makei betrayed the Belarusian people and supported tyranny.
"This is how the Belarusian people will remember him."