The Polish farmers suspended their protest, which aims to secure government subsidies for corn and prevent tax hikes, on Dec. 24. Polish truck drivers have been blocking border crossings with Ukraine since November.

A leader of the farmers' protest in Medyka, Roman Kondrow, told PAP that although Agriculture Minister Czeslaw Siekierski had provided a note telling the farmers their demands would be met, the prime minister had not given a signed declaration.

"We have not received written confirmation that our demands will be met, so we are continuing the protest," he said, adding they would only allow one truck per hour pass through the crossing.

Polish truck drivers have continued to block several crossings since Nov. 6, pressing for the European Union to reinstate a reciprocal system that requires Ukrainian companies to obtain permits to operate in the bloc.

"I will try to convince carriers not to use blockades as a method of defending their interests. We will do everything to effectively protect their interests," Prime Minister Donald Tusk said during a press conference.

"The blockade in the face of bombings and increasingly intense actions from Russia does not make this task easier for us. I will be more effective in working in favour of Polish carriers when there is no blockade."

Tusk said in December that he believed Poland was close to being able to end the truckers' protest.

(Reporting by Karol Badohal, Alan Charlish and Anna Wlodarczak-Semczuk; editing by Barbara Lewis and Elaine Hardcastle)