Malaysia is among 20 nations that gathered on Sunday in northern Saudi Arabia for "the most important" military manoeuvre ever staged in the region.

The Saudi-led military exercise, dubbed “Thunder of the North” involves ground, air, and naval forces, reported SPA, the country's official news agency.

This would send a clear message that the Saudi government and its allies stood united in confronting all challenges and preserving peace and stability in the region, it said.

Other countries include Saudi Arabia's five partners in the Gulf Cooperation Council, as well as Chad, Egypt, Jordan, Morocco, Pakistan, Senegal and Tunisia.

SPA, however, did not specify when the military exercise will begin or how long it would last.

The news agency described it the "most important and largest in the region's history" in terms of the number of nations taking part and the weaponry being used.

Saudi Arabia is currently leading a military campaign against Iran-backed rebels in its southern neighbour Yemen.

It has also formed a new 35-member coalition to fight "terrorism" in Islamic countries.

Last December, Malaysia had pledged to support the coalition to fight against terrorism group IS, but has yet to make a decision on its military commitment.

This was announced by Malaysian's Defence Minister Hishammuddin Hussein before his visit to Saudi Arabia.

Meanwhile, AFP reported that a Saudi source said last Thursday that members of the new "anti-terrorism" coalition will gather in Saudi Arabia next month for its first publicly announced meeting.

Saudi government had said the alliance would share intelligence, combat violent ideology and deploy troops if necessary.