MOSCOW U.S. Vice President Joe Biden arrives in Russia on Tuesday for a visit meant to build on two years of improving ties and prevent the "reset" between the Cold War foes from flagging as elections draw closer.
Shortly after taking office in January 2009, U.S. President Barack Obama launched a campaign to improve relations with Moscow, which had hit a post-Cold War low with Russia's war against pro-Western Georgia in August 2008.
Following are some of the key issues in Russian-U.S. relations:
* NEW START
The treaty setting new limits on the Russian and U.S. arsenals of long-range nuclear weapons is the most prominent element of the reset to date.
Signed by Presidents Barack Obama and Dmitry Medvedev in April 2010 after a year of negotiations, it entered into force last month following approval from lawmakers. [nN05115909]
Each side must reduce deployed strategic warheads to no more than 1,550 within seven years, 30 percent lower than the 2002 Moscow Treaty, and limit the number of deployed delivery vehicles to 700. It also set out rules for verification and monitoring of the U.S. and Russian nuclear arsenals, absent since the 1991 START I treaty expired in December 2009.
* FURTHER ARMS DEALS
The adoption of New START set the stage for potential discussions of further strategic nuclear arms cuts as well as reductions in tactical nuclear weapons, which are a source of tension in Europe.
Both Obama and Medvedev have said the ultimate goal is a world without nuclear weapons, but further cuts will be difficult to secure because of security concerns stemming from issues ranging from tactical conventional arms to third countries with nuclear weapons.
Efforts to cooperate on the long-divisive issue of missile defense are shaping up into a test of U.S. relations with Russia, which has emphasized it could withdraw from New START if a U.S. or NATO missile shield threatens its security by weakening its nuclear deterrent.
Obama shelved a Bush-era plan for long-range interceptor missiles in Poland and a radar station in the Czech Republic, but Moscow says the revised blueprint could still become a threat. Russia is demanding an equal role in a European missile shield or limits on a NATO system.
* SECURITY COOPERATION
Russia has stepped up pressure on Iran over its nuclear program, approving tougher U.N. sanctions last June and outlawing the delivery of S-300 air-defense missiles to Tehran.
Russia has increased support for the U.S. and NATO campaign in Afghanistan, allowing transit across its territory, providing arms for Afghan police and helping to combat opium and heroin trafficking.
Moscow has also seemingly eased off on efforts to have U.S. forces evicted from an air base in Kyrgyzstan that is a major transit center for troops and supplies heading to Afghanistan.
Many analysts say these are responses to the U.S. decisions to seek binding nuclear arms cuts and abandon its Poland and Czech plans, which Moscow said were aimed at weakening it.
However, Russia has said recently that it opposes new sanctions against Iran and that the punitive measures should be eased if Tehran takes specific steps to tackle concerns it could develop atomic weapons.
The United States is supporting Russian efforts to join the World Trade Organization (WTO) as soon as possible. Russia has been seeking membership since 1993 and is the largest economy outside the 153-nation trade rules grouping.
The Kremlin and the Obama administration want the U.S. Congress to remove Russia from the Cold War-era Jackson-Vanik amendment, which tied U.S. trade relations to emigration rights for religious minorities.
Russian officials say they now hope to join the WTO in 2011. If Jackson-Vanik remains in place after Russia joins the WTO, Russia would not be subject to WTO rules in trade with the United States.
A potential obstacle to WTO membership for Russia is Georgia, which has warm ties with Washington. Georgia, whose relations with Russia have remained tense since their brief 2008 war, has warned it could block Russia's entry.
Both countries say they want to foster an increase in trade and investment, which have not lived up to expectations following the breakup of the Soviet Union in 1991.
Russian-U.S. trade totaled $23.5 billion in 2010, just 3.8 percent of Russia's total external trade.
U.S. companies had invested $6.7 billion in Russia since the 1991 Soviet collapse as of last year, less than Ireland or Japan, according to Russian state statistics.
* CIVILIAN NUCLEAR DEAL
A long-sought agreement on civilian nuclear cooperation, similar to deals the United States has with several other countries, entered into force in January after clearing a review period in the U.S. Congress.
(Reporting by Steve Gutterman and Guy Faulconbridge; editing by Sonya Hepinstall)