DAMASCUS: Syrian President Bashar al-Assad has said that "defending" his country in a time of war was more important than any international tribunal that may be brought against his government later.

His comments to Belgian media came as rights watchdog Amnesty International accused the regime of hanging 13,000 at an infamous prison near Damascus.

According to an English-language transcript of the interviews published by Syrian state news agency SANA on Tuesday, Assad accused UN institutions of acting unfairly towards his country.

"We all know that the United Nations institutions are not unbiased, they are biased because of the American influence and the French and British, mainly," he said.

"They are only politicized to implement the agenda of those countries," he added.

Syria's conflict first broke out in March 2011 with widespread protests that descended into violence.

Asked whether he was concerned about a potential court case brought against the regime at the UN's highest court in The Hague, Assad said he and other Syrian officials "don't care".

"For me, as president, when I do my duty, the same for the government and for the army, to defend our country, we don't look to this issue, we don't care about it," he said.

"We have to defend our country by every mean, and when we have to defend it by every mean, we don't care about this court, or any other international institution," Assad added.

The UN General Assembly in December agreed to begin gathering evidence on war crimes in Syria as a first step towards prosecuting those responsible for atrocities there.

At the time, Syria's Ambassador Bashar Jafaari slammed the measure, calling it a "flagrant interference in the internal affairs of a UN member-state."

But in a new report published Tuesday, Amnesty International said Syria's government had carried out a deliberate "policy of extermination" at the Saydanaya military prison.

The report found that as many as 13,000 people were killed in mass hangings at the facility between 2011 and 2015.

-AFP