BEIJING (Reuters) - China is willing to play a constructive role in seeking a political resolution to the crisis over Ukraine, Chinese President Xi Jinping told his Ukrainian counterpart, adding that he considers the eastern European country a friend.

China has walked a fine line over Ukraine since Russian annexed Crimea in 2014, saying it respects Ukraine's territorial integrity and sovereignty but that Western powers should take into consideration Russia's legitimate security concerns.

China and Russia see eye-to-eye on many international diplomatic issues. And, Beijing has been careful not to be drawn into the struggle between Russia and the West over Ukraine's future, not wanting to alienate a key ally in Moscow.

Meeting on the sidelines of the World Economic Forum in Davos, Xi told Ukrainian President Petro Poroshenko that the two countries have a long tradition of friendship, China's foreign ministry said late on Tuesday.

China sets great store on developing ties, and wants to deepen cooperation, Xi said.

"We genuinely hope that Ukraine maintains social stability and economic development, and are willing to play a constructive role in promoting a political resolution to the crisis," the statement paraphrased Xi as saying, without elaborating.

China has previously shown little interest in getting involved in diplomatic efforts to end the crisis.

Poroshenko told Xi that Ukraine welcomed Chinese investment and there was great potential for cooperation in areas like logistics, ports, steel and agriculture, China's foreign ministry added.

Outgoing U.S. Vice President Joe Biden made a call, while in Kiev this week, for sanctions on Russia to stay, urging the world to stand up to its "coercion and aggression" after President-elect Donald Trump mooted ending the measures under a possible deal with Moscow.

(Reporting by Ben Blanchard; Editing by Simon Cameron-Moore)