The UAE accused Qatar on Monday of backing “terrorism and extremism” as the three-year-old Gulf diplomatic crisis returned to the UN’s top court.

Abu Dhabi urged the Hague-based International Court of Justice (ICJ) to throw out a case brought by Doha claiming measures taken against Qatar amounted to racial discrimination.

Saudi Arabia, Bahrain, the UAE and several other allies severed ties with Qatar in a shock move in 2017, accusing Doha of backing terrorism and siding with their regional rival Iran.

They imposed an effective blockade by land, air and sea, and ordered the expulsion of Qatari nationals. Qatar dragged the UAE to the ICJ a year later seeking to get the measures lifted.

The allies faced a “grave threat brought by Qatar’s support for terrorism and extremism”, Abdallah al-Naqbi, director of the international law department at the UAE foreign ministry, told the court via videolink.

“This has nothing to do with racial discrimination.”

Qatar’s case at the ICJ says that the UAE’s actions breached the 1965 International Convention on the Elimination of All Forms of Racial Discrimination (CERD).

Doha is due to give its response on Wednesday, with the rest of the hearings – which are all taking place by videolink due to the coronavirus pandemic – due on Friday and Monday.

But a final ruling by the ICJ, which was set up in 1946 after World War II to rule in disputes between UN member states, could take years.

The court issues binding judgments but has no means of enforcing them.

The crisis between Qatar and the Saudi-led blockading nations shows no sign of relenting despite rising international pressure to end the feud.

The alliance has issued a raft of terms Qatar must accept before it will lift the embargo that includes a ban on direct air, land or sea trade.

Doha strongly denies the allegations and has refused to meet the demands that also stipulate the closure of its flagship State-funded broadcaster Al Jazeera.

The UAE’s Al-Naqbi said that his country and Qatar “share historical bonds dating back to ancient times”, and that Abu Dhabi was “open to close the Gulf rift” with the help of third parties.