Oct. 11 (Bloomberg) -- Secretary of State Condoleezza Rice and Defense Secretary Robert Gates head to Moscow for talks with their Russian counterparts at a time of increasing tension between the former Cold War rivals.

Kosovo is threatening to declare independence from Serbia on Dec. 10 over Russia's strenuous objections unless an agreement on its status is reached. Russian President Vladimir Putin is vowing to quit an accord limiting conventional forces in Europe by Dec. 12 if the U.S. goes forward with a missile defense system in eastern Europe.

``We are well aware of the calendar and well aware that there are some tough issues coming up in December,'' Assistant Secretary of State Daniel Fried said last week.

Putin has moved in recent months to reassert his country's great-power role, using its oil wealth to finance military improvements and staging symbolic events to showcase new capabilities.

On his way to Russia, Gates will stop in London today to meet U.K. Prime Minister Gordon Brown and Defense Minister Des Browne. They plan to discuss Iraq, where Brown has announced plans to reduce British troops to 2,500 by next year, and Afghanistan.

In Moscow, Rice and Gates will focus on missile defense, the conventional forces treaty and ways to extend limits on nuclear weapons when an existing treaty expires in 2009, Fried told reporters. He said he expected the talks, beginning tomorrow, would ``frame up the issues'' for future negotiations rather than reach final resolutions.

Chilly Atmosphere

These disagreements are playing out in an atmosphere that analysts call the chilliest since the Soviet Union collapsed in 1991.

Putin has used Russia's new financial strength as a springboard to challenge arrangements that Russians say were imposed when they were poor and weak, said Dmitri Trenin, deputy director of the Carnegie Endowment for International Peace's Moscow Center.

``As the Russians see it, Russia is up, the United States is down, and Europe is out,'' Trenin wrote earlier this year.

In addition to opposing the U.S. over missile defense, stronger nuclear sanctions against Iran and Kosovar independence, Putin has caught the world's attention by testing a powerful vacuum bomb, resuming regular nuclear bomber flights and laying claim to the North Pole seabed.

In February he accused the U.S. of eroding global security by invading Iraq and Afghanistan and sparking a new arms race with its missile defense plans. ``The U.S. has overstepped its political limits in almost all spheres,'' Putin said.

Avoiding a Fight

President George W. Bush and other U.S. officials have avoided public retorts, shrugged off the Russian moves and eschewed comment on Putin's plan to retain power by becoming prime minister after his presidency ends next year. Bush hosted Putin at Kennebunkport, Maine, in July in an effort to smooth relations.

Still, Rice and Russian Foreign Minister Sergei Lavrov have publicly sparred over Kosovo and missile defense in joint news conferences and were overheard engaging in several frosty exchanges over Iraq during a private lunch in June, 2006, when an audio link in the room was accidentally left on.

The missile defense dispute centers on U.S. plans to base 10 interceptors in Poland and a radar facility in the Czech Republic as part of a system that it says will protect Europe from Iranian rockets. Although Congress is delaying funding, Bush has vowed to go forward with the system.

Missile Defense

Russia says the Iranian threat is unproven and the system could be used to blunt Russia's nuclear deterrent. Putin announced July 14 that Russia would pull out of a 1990 treaty limiting the deployment of conventional military forces in Europe effective Dec. 12.

Putin in June proposed a Russian radar station in Azerbaijan in place of the Czech facility. U.S. officials have expressed interest in the Azeri station but only in tandem with the one in the Czech Republic; they say 10 interceptors pose no threat to Russia, which had 4,162 nuclear warheads deployed as of Jan. 1, according to the Washington-based Arms Control Association.

Missile defense is a ``fundamental issue for Russia,'' according to Fyodor Lukyanov, a Moscow-based foreign affairs analyst who is familiar with Russian government policy.

``Even if the system aims to counter Iran, it will also work against other countries, including Russia,'' said Lukyanov.

Kosovo

Kosovo may prove even more incendiary, said analyst Dimitri Simes, president of the Washington-based Nixon Center.

Russia, seeking to regain influence in the Balkans, has blocked an international settlement that would grant Kosovo independence with safeguards to ethnic Serbs there; the U.S., which asserted its power in the region in a 1999 bombing campaign that drove Serbian forces out of Kosovo, favors such a resolution.

Simes fears a scenario in which the Dec. 10 deadline for a settlement passes, Kosovo declares independence and the U.S. recognizes it.

Russia could retaliate by pressuring the pro-U.S. government of Georgia through annexing Abkhazia and South Ossetia, two regions that broke away from Georgia with Russian military help, Simes said.

Lukyanov said that while he doubted Russia would annex the territories, a Kosovar declaration of independence ``will make the situation a lot more tense in Georgia.''

To contact the reporter on this story: Ken Fireman in Washington at kfireman1@bloomberg.net

Last Updated: October 11, 2007 00:03 EDT