ISTANBUL (RFE/RL)-Azerbaijan's President Ilham Aliyev Wednesday threatened to walk away from negotiations with Armenia to resolve the Nagorno-Karabakh conflict if the long-running peace process yields no breakthrough soon.

Speaking to Azerbaijani journalists during a visit to Istanbul, Aliyev again accused Armenia of dragging feet over international mediators' most recent peace proposals which he said are "on the whole" acceptable to Baku.

"Armenia won't respond [to the proposals,] and I think that the mediating countries must resolutely express their position," he said. He urged the United States, Russia and France, which jointly co-chair the OSCE Minsk Group, to exert a "very serious influence on the Armenian side."

"I have repeatedly stated that we will not take part in negotiations for the sake of imitation," added Aliyev. "We will participate in the process as long as we have hopes for achieving some results.

"Or else, the issue will move from the frozen state to another plane. Namely, the military way. It has never been excluded, and we must always be prepared for that variant."

In recent months, Armenian leaders have repeatedly blamed Baku for the lack of decisive progress in the Karabakh peace talks. But they have yet to clarify Armenia's official position on what the mediators call an "updated version" of their basic principles of a peaceful settlement.

A senior Russian negotiator said in March that the Armenian side has voiced a number of objections to the amended proposals. He declined to specify them.

Officials in Yerevan have instead questioned Azerbaijan's stated acceptance of the document that was originally submitted to the conflicting parties in Madrid in late 2007. They insist that Azerbaijani leaders' statements runs counter to a key element of the Madrid document that envisages a future referendum on self-determination in Karabakh.

They say Karabakh's predominantly Armenian population would be able to vote for the region's independence, reunification with Armenia or, which is extremely unlikely, return under Azerbaijani rule.

"The Azerbaijani leaders' claims that they are ready to grant Karabakh a high degree of autonomy within Azerbaijan are an attempt to predetermine the results of that expression of will and block the application of the principle of peoples' self-determination," Foreign Minister Edward Nalbandian said in the Armenian parliament on Wednesday. He also denounced the Azerbaijani war threats as an attempt to "disrupt the negotiations."

In a speech at a regional security summit in Istanbul on Tuesday, Aliyev again stated that his government would only agree to Karabakh's "high degree of self-rule and autonomy" within Azerbaijan. He made no mention of the proposed referendum.

Practical modalities of the vote are one of the main sticking points in the stalled peace talks. The conflicting parties are also thought to disagree on some crucial aspects of Armenian withdrawal from seven liberated Armenian territories surrounding Karabakh proper.

Azerbaijani Foreign Minister Elmar Mammadyarov met the Minsk Group's U.S., Russian and French co-chairs late last week and said afterwards that they could make "new proposals" in a bid to kick-start the negotiating process. He also said further high-level Armenian-Azerbaijani talks will be possible only if the Armenians display "a sincere desire to achieve progress."

Aliyev noted in that regard that he plans no fresh face-to-face meetings with Sarkisian "anytime soon." He repeated his earlier claims that Sarkisian promised to respond to the proposed Karabakh settlement in two weeks' time when they last met in Sochi, Russia in January. "Six months have already passed, but there is still no news," he said.

In what may have been a related development, Nalbandian on Tuesday had a phone conversation with Russia's Foreign Minister Sergei Lavrov, which was reported by the Armenian Foreign Ministry the next day. A ministry statement said the two discussed Russian-Armenian relations and "exchanged thoughts on regional issues of mutual interest." It gave no further details.