Russian and US negotiators are reported to have agreed the text of an outline deal on cutting Russian and US strategic nuclear arsenals.
The accord will be put to US president Barack Obama and the Russian leader Dmitry Medvedev during their two day summit in Moscow.
There is still great distrust of the US in Russia and Medvedev has said the US will only get a full arms control treaty if it drops unilateral plans for a separate missile defence shield.
Washington says its proposed anti-missile system in central Europe is directed at Iran, but Moscow sees the project as a threat to its own security.
Obama is expected to win the Kremlin’s consent to weapons being taken across Russian territory to NATO forces in Afghanistan.
The two leaders are also expected to create a joint government commission to improve relations between the two countries.
Business leaders travelling with Obama want to use the visit to boost trade and investment.
However, issues such as Russia’s resentment over NATO expansion into the former Soviet Union could cast a shadow.