Mr Medvedev and Cuban President Raul Castro are expected to sign deals on nickel mining and oil exploration.

The Russian leader arrived in Havana from Venezuela, where he and President Hugo Chavez signed a deal on promoting nuclear energy for civilian use.

Military co-operation also featured in Mr Medvedev's talks with Mr Chavez.

After meeting his Cuban counterpart, Mr Medvedev told reporters: "We have a systematic dialogue. Our relations have been generally good, but in the past six months they have become especially intense."

Russian and Venezuelan warships are scheduled to hold joint military exercises later this week.

Russia is already a major arms supplier to Venezuela, with contracts worth some $4.4bn (£2.39bn).

New alignments

Russia companies are interested in drilling for oil in Cuban waters and oil and investing in a nickel processing plant.

The joint exercises are due to begin at sea on 1 December

Cuba is unlikely to want to antagonise the US with President-elect Barack Obama taking office in January, says the BBC's Michael Voss in Havana.

Mr Medvedev's visit was part of a Latin American tour aimed at boosting both Russia's presence and trade ties in a region traditionally of strategic importance to the US.

Boosting bilateral trade between Russia and Latin America, which could reach $15bn (£9.9bn) this year, is another priority for the Russian president during his talks.

The Russian leader travelled to Venezuela from Brazil, where he and President Luiz Inacio Lula da Silva held talks on boosting trade and technical co-operation.

In Rio de Janeiro, the two presidents expressed their view that the "Bric" countries - Brazil, Russia, India and China - should hold their first summit in Russia in 2009.

Mr Medvedev's visit takes place just a few days after the Chinese president, Hu Jintao, toured several Latin American nations with a view to strengthening ties.

BBC