Appeals judges at the International Criminal Court have upheld the conviction of a Congolese war lord who was sentenced to 14 years for recruiting and using child soldiers, bringing to an end the court's first trial.

Thomas Lubanga was convicted in March 2012 of recruiting and using child soldiers in 2002 and 2003, in a verdict hailed as a landmark in international justice and a deterrent that would resonate around the world.

Lubanga, 53, was the first suspect convicted by the international court, 10 years after its creation.

Presiding judge Erkki Kourula on Monday said the five-judge appeals panel rejected all of Lubanga's seven grounds of appeal in a majority decision.