Saudi Arabia declared a UAE-backed separatist advance in Yemen as a threat to Riyadh's national security on Dec. 30 and called Abu Dhabi's actions "highly dangerous", as the conflict boiled over into an open dispute between the Gulf powers.
The strongly worded Foreign Ministry statement came after the Saudi-led coalition fighting in Yemen said it had struck a United Arab Emirates weapons shipment destined for separatist forces.
In recent weeks, separatists backed by Abu Dhabi and seeking to revive the formerly independent state of South Yemen have made sweeping territorial gains after launching a lightning offensive in recent weeks.
The leader of Yemen's presidential council, which sits atop that government, declared a state of emergency and cancelled a security pact with Abu Dhabi after the forces of the UAE-backed Southern Transitional Council (STC) seized swathes of territory.
The STC is also part of the government, a fractious patchwork of groups held together by its opposition to the Iran-backed Houthi rebels who control swathes of northern and western Yemen including the capital Sanaa.
Saudi Arabia and the UAE, traditionally close allies who joined forces in Yemen against the Houthis, have increasingly been at odds over the conflict on their doorstep, as well as the war in Sudan.
"The Kingdom [Saudi Arabia] expresses its disappointment by the actions taken by the brotherly United Arab Emirates, pressuring the Southern Transitional Council's forces to conduct military operations on the southern border of the Kingdom," the Saudi statement said.
It called them "a threat to the Kingdom's national security, as well as to security and stability in the Republic of Yemen and the region," it said.
