A separatist group in Yemen backed by the United Arab Emirates (UAE) agreed on Thursday to the deployment of forces aligned to Saudi Arabia to the southern regions it took control of last month.

Saudi Arabia and the UAE entered the Yemen war as allies in 2015 to defeat the Iran-backed Houthis and restore the internationally recognized Yemeni government. 

However, their alliance fell apart over conflicting visions for Yemen’s future, with Saudi Arabia supporting the central government and the UAE helping to build the separatist group in the south.

What did the separatist movement say?

In a statement, the Southern Transitional Council (STC) separatist group said it would continue to operate in Hadramout and al‑Mahra provinces that were seized in December, adding that it had agreed to the deployment of Saudi-backed National Shield government forces to those areas.

"Today, we launched an operation to integrate the southern National Shield forces so that they can assume the responsibilities and missions that fall to our armed forces," the STC announced.

The separatists said they want to protect the progress made against the Houthis last month when STC forces took control of those regions.

Why are Hadramout and al-Mahra contested?

Hadramout borders Saudi Arabia and is home to Yemen's largest oil fields and the Dhabba oil terminal on the Arabian Sea.

Al-Mahra, meanwhile, has proposed routes for new oil pipelines that will allow Saudi oil exports to bypass the Strait of Hormuz. The Strait is a major chokepoint for global oil trade, which Iran has repeatedly threatened to blockade.

The Saudi government has repeatedly urged the STC to withdraw from the two territories, particularly areas along its southern border, to protect its national security.

The AFP news agency cited a source close to the Saudi government as saying that STC's redeployment was not enough and that Riyadh's security concerns would only be fully addressed if the separatists moved out of Hadramout and al-Mahra.

Saudi strikes spur UAE 'face-saving'

Tensions between the two Gulf powers further escalated on Tuesday after the Saudi‑led coalition in Yemen struck what it said was a shipment of Emirati weapons bound for separatist forces at the port of Mukalla, which sits in Hadramout.

The UAE rejected the allegation and called for STC fighters to pull back from the territory they recently seized.

The UAE's Defense Ministry later said it would withdraw its last remaining troops in Yemen. Most UAE troops left the war-ravaged country in 2019.

Risk of Southern Yemen seeking full independence

The STC's offensive last month heightened the possibility that South Yemen — which existed as a sovereign state between 1967 and 1990 — might pursue independence.

Farea Al-Muslimi, a Gulf and Yemen researcher at the UK-based Chatham House think tank, views the partial deployment agreement as little more than a face-saving measure, not a genuine resolution to the rift.

The STC now controls nearly all of pre-1990 South Yemen, including the strategic port city of Aden — Yemen's main commercial hub — as well as the island of Socotra.

This near-total control over the old southern territory dramatically increases the chances of the STC pushing for full independence, as Aden's economic and symbolic importance makes any split from the north far more viable.

Analysts also believe the possible collapse of Yemen's coalition against the Houthis, which has been limited and largely stalled in recent years, remains very real.

The United States, European Union and United Nations have urged calm, warning that the latest escalation risks deepening divisions in Yemen.

The Houthis control roughly one-third of Yemeni territory — mainly the populous north and west, including the capital Sanaa. The STC now effectively controls about half of Yemen's total territory, with the Saudi-backed Yemeni government controlling less than 15%. 

Edited by: Dmytro Hubenko