Russian President Vladimir Putin is urging President Bush to step up joint efforts in the fight against terrorism, which he has called the plague of the 21st Century.

President Putin says cooperation between Moscow and Washington must be expanded to fight what he called the barbaric actions of terrorists.

In a statement issued by the Kremlin, Mr. Putin also thanked President Bush for his support after last week's deadly bombing on the Moscow metro that killed 39 people and wounded well more than 100 others.

President Putin also hailed progress in bilateral relations between the two countries, saying the partnership between the two countries was "unbreakable."

The U.S.-Russian relationship was seriously tested early last year, with President Putin's strong opposition to the U.S.-led war in Iraq, which he called a serious mistake at the time. Both sides have moved since then to repair relations, but some tensions still remain.

Last month, Secretary of State Colin Powell expressed concerns about the slow development of the rule of law in Russia. He said political power was not yet fully tethered to law. Mr. Powell also challenged Russia's policy on Chechnya, saying certain aspects of Russian internal policy in the southern Russian republic give the United States cause for concern.

Mr. Putin, who was the first to join the U.S.-led global coalition against terrorism, did not address those concerns in his statement on Wednesday. Instead he focused on military cooperation and other ties, and said Russia's aim is to build a close friendship with Washington.

Mr. Putin's message was delivered by his chief of staff, Dmitry Medvedev, while on a visit to Washington. He met White House Chief of Staff Andrew Card and Secretary of State Colin Powell for talks on Russian-U.S. cooperation.