The top prosecutor for the International Criminal Court says he will seek “close to the maximum” sentence for Thomas Lubanga, the Congolese warlord convicted of recruiting and using child soldiers.

ICC prosecutor Luis Moreno-Ocampo spoke at The Hague Thursday, a day after the court convicted Lubanga of war crimes in its first verdict since being established a decade ago.

Under the court's founding treaty, the Rome Statute, Lubanga faces a maximum of 30 years or life in prison. According to the document, life in prison is justified by the “extreme gravity of the crime and the individual circumstances of the convicted person.”

In a unanimous ruling, the court ruled that Lubanga recruited children under 15 years old to fight for the armed wing of his group, the Union of Congolese Patriots.

The militia group fought during the Democratic Republic of Congo's civil war in 2002 and 2003.

Lubanga will remain in custody until his sentencing at a later hearing. He can still appeal the verdict.

The ICC's verdict on Wednesday drew international praise from rights group and governments.

The United States said the ruling provided justice and accountability to the Congolese people.

The United Nations said the verdict showed a commitment by the international community to ensure anyone who commits crimes against children during conflict will be held accountable.