Only a handful of US marines remained on the island after the 1,600-strong force began withdrawing in the past two weeks, the official said, adding that they too would be leaving shortly.

Troops from Austria, Belgium, Canada, Greece, India, Italy and Pakistan had also drastically reduced their strength in the last few days and were on the verge of completing a withdrawal, the official added.

More than a dozen countries rushed troops to help with the immediate relief operations after the December 26 tsunamis killed nearly 31,000 people and left a million homeless in Sri Lanka.