Washington wants to see constructive relations between Ukraine and Russia, and supports Kiev''s right to make its own choices, a spokesman for the U.S. Department of State said.

"It is important for Ukraine and Russia to have a constructive relationship," Philip Crowley said on Wednesday, after being asked to comment on the Russian president''s recent "scathing attack" on his Ukrainian counterpart.

Russian President Dmitry Medvedev blamed Ukraine''s Viktor Yushchenko on Tuesday for the worsening in relations between the two former Soviet republics, expressing his "deep concern at the current, without exaggeration, crisis in Russian-Ukrainian relations."

Relations between Moscow and Kiev have been marred in recent years following a number of gas disputes, Ukraine''s desire to join NATO, and the Soviet-era famine in Ukraine.

Crowley also reiterated the U.S.''s support for Ukraine''s right as a sovereign state to pursue its interests "in any way that it chooses."

"Going forward, Ukraine has a right to make its own choices, and we feel that it has a right to join NATO if it chooses," the U.S. official said.