"I've have said before that I am not a candidate for any other job than the one I have now, and this has not changed after my meeting with the U.S. president," Frederiksen told reporters outside the White House.

NATO Secretary-General Jens Stoltenberg is due to step down from his position later this year.

Speculation about Frederiksen as a serious contender for the job has intensified since her name first surfaced publicly in a report by Norwegian newspaper VG last month.

Frederiksen told reporters she had met with Burns during her trip to Washington, but did not give further details.

Her meeting with Biden was scheduled to take 45 minutes, but lasted about two hours.

(Reporting by Jacob Gronholt-Pedersen and Andrea Shalal; Writing by Katharine Jackson; editing by Costas Pitas and Eric Beech)