SHANGHAI, May 20 -- China and Russia expressed "grave concern" over the political crisis in Ukraine in a joint statement signed here on Tuesday.

Chinese President Xi Jinping and Russian President Vladimir Putin signed the joint statement after holding talks earlier in the day.

According to the statement, the two sides urge all parties concerned to exercise restraint, avoid escalating the conflict and seek a peaceful and political settlement for the current problems.

The statement calls on all local and sociopolitical groups in Ukraine to participate in a comprehensive national dialogue, and jointly develop a concept for the future constitutional development of the country, in an effort to fully protect the citizens' basic rights and freedom.