WARSAW, Jan 21 (Reuters) - Poland"s prime minister on Friday called on European leaders to take a tough, united stance towards Russia amid fears that Moscow could be readying an invasion of Ukraine. Ukrainian President Volodymyr Zelenskiy concluded two days of talks with his Polish counterpart Andrzej Duda on Friday, and Poland has said that Kyiv can count on its support in the event of a Russian attack. However, Warsaw has not announced precise details of the form this support could take. "Poland unequivocally supports Ukraine in its pro-Western aspirations," Prime Minister Mateusz Morawiecki said in a podcast. "In the face of Russian threats, European unity and solidarity is key for Ukraine. Russia must know that it is dealing with a united front without exceptions." Western states fear Moscow is planning a new assault on Ukraine after sending in forces into the former Soviet republic 2014 to annex the Crimea peninsula. Russia denies planning an attack but says it could take unspecified military action if its security demands are not met. Following the talks in the southern Polish town of Wisla, President Duda also stessed Poland"s support for Kyiv. "Poland rejects the concept of spheres of influence and supports full Euro-Atlantic integration of Ukraine," he wrote on Twitter. Duda"s foreign affairs advisor Jakub Kumoch told Reuters by text message that a special channel for continued contact between Poland and Ukraine would be established, with further talks between presidential representatives lined up. "The Euro-Atlantic community has a duty to counteract any aggression, regardless of its size and scale," Kumoch said.