KIEV, Jan. 22 – Russia warned Ukraine on Tuesday that Kiev’s accession to NATO would “seriously aggravate” relations between the two countries and would probably trigger unspecified sanctions from Moscow in response.

The warning comes days after Ukraine formally asked NATO for permission to join the Membership Action Plan, the last program preceding accession to the alliance, in April.

“Ukraine’s possible integration into NATO will seriously aggravate multi-dimensional Russian-Ukrainian relations,” the Russian Foreign Affairs Ministry said in a statement. “We will be forced to take adequate measures.”

The warning is the strongest reaction from Moscow yet since Ukraine has sought to accelerate its accession to NATO by formally asking to join the MAP. Although there is no particular time frame, a country usually accedes to NATO between one to two years after joining the MAP.

Russia did not specify the possible sanctions it may impose, but analysts said cooperation in military and defense sector, such as joint production of arms, will probably be curtailed.

Russia, Ukraine’s only supplier of natural gas, may also seek to further increase gas prices it charges Ukraine by bringing them closer to the average European gas prices, analysts said.

Ukraine currently buys gas from Russia at $179.5 per 1,000 cubic meters, up from $130/1,000 cu m last year, but the average gas price in Europe exceeds $300/1,000 cu m, analysts said.

Russia apparently fears that Ukraine’s accession to NATO would present a major security threat as Moscow claims the alliance has been resorting to practices leftover from the Cold War. The statement did not elaborate.

“The new radical expansion of NATO may lead to serious military and political shift that will inevitably affect security interests of Russia,” the statement said. NATO is “an organization, whose transition to new, different from the Cold War, realities are far from completion,” the statement said.

Ukraine seeks to join the MAP in April, at a NATO-Ukraine summit scheduled to take place in Bucharest.

President Viktor Yushchenko, Prime Minister Yulia Tymoshenko and Parliamentary Speaker Arseniy Yatseniuk signed the formal request to join the MAP in a letter submitted to NATO Secretary General Jaap de Hoop Scheffer.

“Completely sharing European democratic values the country sees itself as a part of the Euro-Atlantic security space and is ready together with NATO and its partners to counteract joint security threats,” the letter said.

Oleh Bilorus, the chairman of the Foreign Affairs Committee in Parliament, said Moscow has been resorting to a “savage” reaction, and warned that Kiev may also response with sanctions.

“Sanctions are a bilateral thing,” said Bilorus, a member of the group led by Prime Minister Yulia Tymoshenko. “Things like that must be actively reacted to.” (tl/ez)