The Polish army says it has detained some 100 migrants who had illegally crossed into Poland from Belarus overnight, alleging that the Belarusian army had helped them make the intrusion.

Russia denounces Poland's use of tear gas and water cannon against migrants trying to cross into the country from Belarus, describing the move as "absolutely unacceptable."

Washington on Monday said it was pressing ahead with new measures targeting the administration of President Alexander Lukashenko while in Brussels EU foreign ministers met to expand sanctions on Belarus.

In a phone call with his French counterpart Emmanuel Macron on Monday, Putin drew attention to what he called provocative nature of the large scale exercises led by the US and its allies in the Black Sea

It’s called a Belarus-Poland border crisis, and the EU is faulting Belarus. It has decided to widen Belarus sanctions as the row intensifies.

Belarus is accused by the EU of triggering the crisis on its border by flying in thousands of asylum-seekers and pushing them to try to cross into Poland.

Polish Prime Minister Mateusz Morawiecki says Poland, Lithuania and Latvia may ask for consultations under the alliance’s treaty, suggesting further sanctions against Belarus.

Russian president says Moscow is fully prepared to help resolve a migrant crisis on the border between Belarus and Poland.

The situation is spiraling out of control at the Poland-Belarus border, where thousands of migrants remain stranded for many days, amid a bitter political standoff.

Belarus says it intends to deploy Russian nuclear-capable Iskander missile systems in the south and west of the country.