Russian President Dmitry Medvedev speaks during a news conference at the NATO-Russia Council summit in Lisbon, the capital of Portugal, Nov 20, 2010. [Photo/Xinhua]

LISBON - Just getting the leaders of Russia and NATO around the table to talk about increased cooperation was progress barely two years after the Georgian war triggered a near freeze in relations.

In Lisbon, Russian President Dmitry Medvedev and his NATO counterparts agreed to work together to fight piracy, terrorism, narcotics trafficking and the spread of weapons of mass destruction. But a much-vaunted agreement to cooperate on missile defense appears less conclusive that the alliance had initially hoped.

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Medvedev also made clear that a threat by Republicans in the US Congress to hold up ratification of the START treaty on nuclear disarmament would be a new dampener to reviving relations between Moscow and Washington.

"That would be very unpleasant," Medvedev warned reporters in response to a question about a START delay. "If we fail to move this question forward the world will not become safer."

NATO leaders had been upbeat about the prospect of Russia agreeing to cooperate in a new multi-layered system of anti-missile defenses which the 28 North Atlantic Treaty Organization nations signed up on Friday.

"For the first time in history, NATO and Russia will be cooperating to defend themselves," NATO Secretary General Fogh Rasmussen said after the allies met with Medvedev.

"Starting today we will begin working on missile defense cooperation to protect our deployed troops on the ground and we will answer the questions that need answering for us to cooperate on territorial missile defense as well," he added in carefully chosen works which showed the limitations on the cooperation Medvedev had signed up to.

Russia had long been engaging in a cooperation project with NATO to improve so-called "battlefield missile defenses" against the risk of short-range attack to troops. Those talks had stalled after the August 2008 Georgian war but will now resume.

Territorial missile defense is a different issue involving US plans to include Europe in a global shield against long-range missile attack. Here Russia remains wary of NATO's intentions and agreed only to an assessment of the possible threats and "dialogue " leading up to a possible decision at meeting of defense ministers in June 2011.

Medvedev gave the NATO leader a stark warning about the dangers of pressing ahead with their plan, should those talks fail to produce a result that eases Russian concerns.

"If we fail to agree on missile defense, it could be a new arms race coming our way," he told a news conference.