WARSAW (REUTERS) - Polish foreign minister Radoslaw Sikorski said on Tuesday Russia has gathered military forces at the border with Ukraine to either put pressure on the neighbouring country or to enter it.

"Unfortunately, Russia has restored its combat capability on the border with Ukraine," Sikorski told TVN24 broadcaster.

"There are several battalion groups there. There is a large concentration of military hardware there. These things are being done just to exert pressure. Or to enter," he said.

Asked which option would be chosen he answered: "We'll see. We will know it very quickly."