Washington is “concerned” over the Southern Transitional Council in Yemen declaring self-rule at the weekend, Secretary of State Mike Pompeo said as he warned such actions threatened efforts to revive talks between the Yemeni government and Houthi rebels.
Saudi Arabia, the UAE and the Arab Coalition to support the internationally recognised government have urged the STC to return to the table and discuss a deal brokered in Riyadh last November to end tensions between the government and the southerners, a key military component in the pro-government battle against Houthi rebels.
"Such unilateral actions only exacerbate instability in Yemen," Mr Pompeo said. "They are especially unhelpful at a time when the country is threatened by Covid-19 and also threaten to complicate the efforts of the UN Special Envoy to revive political negotiations between the government and the Houthi rebels."
The Saudi Cabinet late on Tuesday also called for the STC to roll back the move and return to the Riyadh agreement and work with partners to accelerate the implementation of its terms.
The council, who met online, also discussed the coalition’s unilateral ceasefire prompted by a United Nations plea to focus on the coronavirus pandemic. Despite the Houthis not accepting a ceasefire and continuing to launch attacks, the coalition has extended the truce through Ramadan.
Yemen's internationally recognised government warned of "catastrophic consequences" after the STC on Sunday declared emergency rule in southern governorates including Aden, the interim seat of the government that was ejected from power in the capital, Sanaa, by the Houthi group in late 2014.
"We call on the STC and the Republic of Yemen government to re-engage in the political process provided under the Riyadh Agreement," Mr Pompeo said.
On Monday, the Saudi-led coalition engaged in Yemen urged the STC to rescind its move, saying it was an "escalatory action" at a time when all parties should focus on confronting the coronavirus.
Yemen has been mired in violence that has killed more than 100,000 since the coalition intervened in March 2015 on the side of Abdrabu Mansur Hadi's government. There has been military stalemate for years and the Houthis hold most big urban centres.
The STC has long sought self-rule in the south and accuses Mr Hadi's government of mismanagement and corruption, a charge it denies.
While Yemen has reported only one confirmed Covid-19 case, the UN warns it is probably circulating in the country and aid groups fear a catastrophe if it spreads among a malnourished population in a country with a shattered health system.
The UN has warned that Yemen could expect as many as 16 million coronavirus cases and the "most likely scenario" is for about 55 per cent of the population to get it.
The United Nations is trying to convene virtual talks on the truce, co-ordinated coronavirus efforts and confidence-building steps to restart talks to end the war.