War crimes judges on Monday delivered a slap to Jordan, referring the Arab country to the United Nations for action for failing to arrest the visiting Sudanese president wanted on genocide charges.

Despite two international warrants for his arrest on 10 charges arising from the conflict in Darfur, Sudanese President Omar al-Bashir freely attended an Arab League summit in Amman in March.

Judges at the International Criminal Court (ICC) ruled that "Jordan failed to comply with its obligations ... by not executing the court's request for the arrest of Omar al-Bashir and his surrender to the court while he was on Jordanian territory on 29 March 2017".

Jordan is a member of the Rome Statute, which underpins the tribunal - established in 2002 to try the world's worst atrocities - and as such has agreed to comply with the court's orders.

The ICC issued arrest warrants for Bashir in 2009 and 2010, but he has so far evaded arrest and steadfastly denies the charges related to the conflict in war-torn Darfur.

The judges decided that Jordan's "non-compliance" should be referred to the UN Security Council as well as the tribunal's own Assembly of State Parties.

But it is unlikely there will be much further action taken at the UN.

In July the judges already ruled that South Africa had flouted its duties to the ICC in 2015 by failing to arrest Bashir, when he attended an African Union summit.

But presiding ICC judge Cuno Tarfusser, who also signed Monday's order against Jordan, decided that it would be "effectively futile" to refer Pretoria to the UN.

There have been six previous referrals of various countries to the Security Council for allowing Bashir to travel freely on their territory.

Pretoria's lawyers had argued at an April ICC hearing there "was no duty under international law on South Africa to arrest" Bashir.

But the judges ruled international obligations cannot "simply be put aside" if a country disagrees with them, and said Bashir did not enjoy immunity.