A search is under way in southern Afghanistan for a soldier from the NATO-led coalition, believed to be the first to have gone missing since a U.S. Army sergeant was captured by the Taliban more than three years ago, a military spokesman said Friday. U.S. Army Maj. Martyn Crighton said the soldier was among the 1,560 troops from the former Soviet republic of Georgia serving in the country. A statement from Georgia's Defense Ministry on Thursday said an intense "search and rescue" operation was being mounted in Helmand and Nimroz provinces, describing the soldier as a military officer who went missing on Wednesday. The last known coalition soldier to go missing was U.S. Army Sgt. Bowe Bergdahl, 26, who was taken prisoner on June 30, 2009 in Paktika province in southeastern Afghanistan. Bergdahl, who turned 26 in captivity on March 28, was the subject of a proposed prisoner swap in which the Obama administration was considering the transfer of five Taliban prisoners long held at the U.S. military prison at Guantanamo Bay, Cuba, to Qatar. That plan collapsed, but a new proposal would transfer some Taliban fighters or their affiliates out of full U.S. control. The prisoners would go to a detention facility adjacent to Bagram air field, the largest U.S. military base in Afghanistan, officials of both governments have said. Eighteen Georgian soldiers have been killed since the country joined the international military operations in Afghanistan in August 2009. Georgia is not a member of NATO but has significant presence in Afghanistan relative to its population of 4.5 million.