MOSCOW/ MINSK — Russia's Foreign Minister Sergei Lavrov has postponed a planned visit to Minsk following the death of his Belarusian counterpart Vladimir Makei, according to Russian media reports quoting the Foreign Ministry.

Belarus's state news agency Belta reported on Saturday that the long-standing foreign minister and associate of authoritarian leader Alexander Lukashenko had died suddenly. The cause of death wasn't given and Makei wasn't known to suffer from any chronic illness.

Makei, 64, was due to meet Lavrov on Monday. Last week he attended a conference of the Collective Security Treaty Organization (CSTO) — a military alliance of several post Soviet states — in Yerevan.

Before the controversial presidential elections in Belarus in 2020 — which were widely seen as rigged and triggered mass anti-government protests — Makei had been one of the initiators of efforts to improve Belarus' relations with the West and had criticized Russia.

However, he abruptly changed his stance after the start of the protests, saying they were inspired by agents of the West.

Exiled opposition leader Sviatlana Tsikhanouskaya, commenting on the minister's death called Makei a traitor to the Belarusian people.

"In 2020, Makei betrayed the Belarusian people and supported tyranny. This is how the Belarusian people will remember him," Tsikhanouskaya said on Twitter.

A few days before Russia's invasion of Ukraine began in February, Makei promised there would be no attack on Ukraine from the territory of Belarus. The entry of Russian troops into Ukraine proved that he was wrong.

A supporter of close ties between Moscow and Minsk, Makei said the West had provoked the war and that the Ukrainian authorities should agree to the Russian terms of peace.

In September, he defended Belarus' position to the United Nations Security Council, rejecting claims that his country was an "accomplice to the aggressor" or a party to the conflict.

Lukashenko, who crushed the protests of 2020 and retained power in Belarus, offered his condolences to Makei's family, according to the presidential office.

In Moscow, Russian Foreign Ministry spokeswoman Maria Zakharova said that ministry officials were shocked by the news of Makei's death. — Euronews