U.S. Vice President Joe Biden praised Mongolia's transition to democracy Monday during a 1-day visit that featured talks on closer economic and defense cooperation.

Biden arrived in Ulan Bator after a 5-day trip to China. He is the first U.S. vice president to visit Mongolia since 1944, though former president George W. Bush made a brief stopover in 2005.

Biden thanked the country for its contributions to military operations in Iraq and Afghanistan as well as other peace-keeping operations.

The vice president was returning a visit to Washington in June by Mongolian President Tsakhia Elbegdorj. He also met Monday with Prime Minister Sukhbaatar Batbold.

Despite a generally warm welcome in Mongolia, Biden's motorcade was greeted by a small group of protesters with signs urging America to “keep your hands off Mongolia.”

An American company, Peabody Energy Corporation, was among several bidders awarded rights in June to help develop Mongolia's Tavan Tolgoi coalfield, one of the world's largest deposits of coking coal. New discoveries of coal, copper and rare earths have the potential to triple Mongolia's GDP over the next decade.

Mr. Biden said the United States has grown “much closer” to Mongolia since the former Soviet satellite state turned to multi-party democracy in the early 1990s.

Biden is scheduled to continue Monday evening to Tokyo, where aides say he will express steadfast U.S. support for Japan following the March 11 earthquake, tsunami and nuclear emergency. He will also thank U.S. civilian and military personnel who aided the disaster response.

While in China, Biden met with President Hu Jintao, Premier Wen Jiabao and other top officials for talks that focused on economic issues. He praised China's economic growth, but also expressed confidence in the future of the U.S. economy, by far the world's largest.

Biden's visit comes less than two weeks after an unprecedented U.S. credit downgrade – a move that sparked global concerns about the safety of dollar assets.