Suspected Russian arms dealer Viktor Bout arrives at a Bangkok criminal court October 5, 2010. A Thai court on Tuesday dismissed charges of money-laundering and wire fraud against Bout, bringing him a step closer to extradition to the United States. [Photo/Agencies]

BANGKOK - Thai Prime Minister Abhisit Vejjajiva said suspected Russian arms dealer Viktor Bout could be extradited to the United States to face terrorism charges later on Tuesday, a few days before his detention is due to expire.

"It should be today, if it is possible," Abhisit told reporters, adding that the cabinet had earlier on Tuesday officially acknowledged a US extradition request.

The 43-year-old former Soviet air force officer, dubbed the "Merchant of Death", faces US accusations of trafficking arms since the 1990s to dictators and conflict zones in Africa, South America and the Middle East.

He has been fighting extradition since his March 2008 arrest in Bangkok as part of a US-led sting operation and legal wrangling over his fate led to a two-year diplomatic tug of war between Washington and Moscow.

A photographer said dozens of policemen and masked commandos guarded the entrance of Bangkok's maximum-security Bangkwang prison where Bout has been detained, apparently waiting to take him to an air force base for a flight out.

A Thai court had earlier cleared the way for Bout's extradition but the executive branch could have blocked it if it was deemed to be detrimental to foreign relations or harmful to individuals involved.

"The cabinet acknowledges the appeal court's judgement that the case was not a political one so we did not oppose his extradition," Deputy Prime Minister Trirong Suwannakhiri told Reuters.

Russia's Foreign Ministry has said Bout is an innocent businessman facing a politically motivated extradition that could undermine strengthening US-Russian ties and undo the White House's efforts to "reset" relations between the Cold War foes.

Bout, an inspiration for the Hollywood movie "Lord of War" starring Nicholas Cage, has been held in prison since his arrest in a joint US-Thai sting operation in which agents posed as arms buyers for the Revolutionary Armed Forces of Colombia.