Iran's supreme leader has held talks with a senior Yemeni rebel official just days after the long-running intervention against the rebels by its regional foes Saudi Arabia and the UAE suffered a major setback.
Ayatollah Ali Khamenei hosted Huthi rebel spokesman Mohammed Abdul Salam at his Tehran residence late Tuesday after southern separatists backed by the United Arab Emirates seized Yemen's second city Aden on Saturday.
The defeat for President Abedrabbo Mansour Hadi's unionist supporters, who have been backed by Saudi Arabia, exposed the divergent ambitions of the key coalition partners and threatened to weaken their common struggle against the Huthis.
Khamenei renewed his support for the rebels, who control the Yemeni capital Sanaa and much of the north, and accused Iran's foes of a "plot" to partition the country.
"I declare my support for the mujahidah (struggle) of Yemen," he said in a statement issued after the talks.
"Saudi and UAE and their supporters have committed major crimes in Yemen.
"They seek to divide Yemen. This plot should be strongly resisted and a unified, coherent Yemen with sovereign integrity should be endorsed," the Iranian leader said in an English-language statement.
South Yemen was an independent country until it merged with the north in 1990. An armed secession bid four years later ended with its occupation by northern forces, which provoked resentments that persist to this day.
Four and a half years of Saudi- and UAE-led military intervention in support of Hadi has seen the Huthi rebels pushed out of the south.
But the UAE, which has led ground operations in the region, has relied heavily on southern separatists at the expense of the unionists, who dominate Hadi's government.
Khamenei called for talks to stop Yemen being divided.
"Given Yemen?s religious and ethnic diversity, protecting Yemen's integrity requires domestic dialogues," he said.
The conflict has claimed the lives of tens of thousands of people and displaced some 3.3 million since 2015. Two-thirds of the population -- some 20 million people -- require humanitarian support, according to the United Nations.
Khamenei blasted the "Western world's indifference towards the crimes committed in Yemen".
"The Islamic republic's anti-US and anti-West stances are not out of fanaticism," he said.
"Rather, they're based on realities, US politicians' and West's actions, who fake a humane, civilised and ethical appearance while committing the worst crimes and talking about human rights."
The United States and its Western allies have kept up huge arms sales to Saudi Arabia and the UAE, despite an international outcry over the human cost of the war.
Saudi Arabia and the UAE have repeatedly accused Iran of supplying weapons, including ballistic missiles, to the Huthis rebels, an accusation Tehran has consistently denied,
Iran's supreme leader Ayatollah Ali Khamenei has renewed support for Yemen's Huthi rebels in talks with their spokesman Mohammed Abdul Salam, and accused Saudi Arabia and the United Arab Emirates of a "plot" to partition the war-torn country