In an effort to tackle a migrant crisis on the border with Belarus, Poland has moved 15,000 troops to the frontier, put up a fence topped with barbed wire and approved the construction of a wall.

Khrenin said it appeared that Poland wanted to drag Europe into a full-blown military conflict with Belarus and that the build-up of foreign troops on the Belarusian border was "in no way connected" with the migrant crisis.

"The Belarusian armed forces are ready to respond harshly to any attacks," Khrenin said in a video address. "The language of ultimatums, threats and blackmail is unacceptable."

"We'd like to warn hotheads against overestimating their capabilities," he said, stressing that Belarus' ally Russia was ready to help ensure the country's security.

Hundreds of migrants, mainly Kurds from the Middle East, have been stuck for days on the Belarus-Poland border in near-freezing temperatures, with the World Health Organization saying it was "very concerned" about their plight.

Poland is refusing to allow them to cross, with the West accusing Belarusian leader Alexander Lukashenko of bringing them into the country to send over the border in revenge for sanctions.

In a show of support for Minsk, Russia has sent strategic bombers to patrol over Belarus this week and on Friday the two countries said a joint battalion of paratroopers was holding snap drills near the Polish border.