RIYADH, Dec. 30 (Xinhua) -- The Saudi Cabinet on Tuesday called on the United Arab Emirates (UAE) to withdraw its forces from Yemen within 24 hours and end all support for separatist groups, signaling a sharp public rift between the two Gulf powers.

The statement, carried by the state-run Saudi Press Agency, warned that Riyadh would take "necessary steps" to protect its national security and described recent developments as an "unjustified escalation" that undermines stability and contradicts the principles of the Saudi-led coalition.

Tensions have risen over the actions of Yemen's Southern Transitional Council (STC), which recently seized large swathes of the oil-rich Hadramout province and the eastern governorate of Al-Mahrah, territories Riyadh considers a "red line" due to their proximity to Saudi Arabia and concentration of Yemen's remaining energy reserves.

The Saudi Cabinet expressed regret over failed de-escalation efforts and accused the UAE of not honoring previous commitments, reiterating full support for Yemen's Presidential Leadership Council (PLC) and its chairman, Rashad al-Alimi.

The STC, despite being part of the PLC, has long promoted southern Yemeni independence and accused the internationally-recognized government -- now based in the southern city of Aden after being ousted by Houthi forces in 2014 -- of failing to counter Houthi offensives.

The secessionist group commands significant control in Aden and other southern cities, reportedly receives support from the UAE, which has upset Saudi Arabia, the main backer of the recognized government.

Earlier on Tuesday, the UAE Ministry of Defense said it would withdraw its remaining forces from Yemen, citing concerns that recent developments "could affect the safety and effectiveness of its counterterrorism operations." The ministry did not provide a timeline and denied pressuring any Yemeni party to carry out operations threatening Saudi security.

The diplomatic fallout escalated after a Saudi-led coalition airstrike targeted vehicles at the port of Mukalla in Hadramout, which Riyadh said were intended for STC forces. The UAE Ministry of Foreign Affairs denied the claim, saying the shipment contained no weapons and had been coordinated with Saudi authorities.

Following the strike, Yemen's leader al-Alimi canceled a joint defense agreement with the UAE and ordered all Emirati forces to leave within 24 hours.

The public dispute marks a shift for the Gulf powers, who have traditionally relied on quiet diplomacy to manage differences in Yemen, and poses the most significant challenge to their shared regional strategy in years.