Brussels - NATO Secretary General Jaap de Hoop Scheffer underwent treatment in a hospital Tuesday after suffering from a minor blood clot, the alliance said.

The procedure was successful and de Hoop Scheffer was expected to completely recover. He will remain in the hospital for a few days for observation, NATO said in a statement.

The 61-year-old native of the Netherlands is due to step down at the end of July after five years in the post. Former Danish prime minister Anders Fogh Rasmussen was named as his replacement.

A US State Department spokesman in Washington said the United States was hopeful de Hoop Scheffer will quickly recover.

"We're very relieved that he is OK, and we send him our best wishes and hope that he will have a very speedy recovery," Robert Wood said.(dpa)