The UN Security Council has told Yemen's former president and vice president that they could face possible sanctions along with others reported to be interfering in the country's democratic transition and undermining the national unity government.
Saturday's statement approved by all 15 council members said the Security Council is ready to consider non-military sanctions if such actions continue.
It expressed concern at reports of meddling in the transition by members of the former regime, former opposition, and other opponents of the current government, singling out former President Ali Abdullah Saleh and former Vice President Ali Salim Al-Beidh.
Yemen has been struggling with a transition to democracy since Arab Spring protests a year ago forced Saleh to step down after 33 years as president.
A transitional government led by President Abed Rabbu Mansour Hadi is trying to promote national reconciliation, draft a new constitution and hold elections.
Mark Lyall Grant, Britain's UN ambassador, said the statement was a clear message to Saleh "that the actions that he and other are taking to undermine this process will not be tolerated".
Lyall Grant said that during a Security Council mission to Yemen three weeks ago members heard concerns about Saleh and other "spoilers" undermining a national dialogue conference, which Hadi has scheduled to start on March 18.
|For more on Yemen, visit our Spotlight page
"What he should not do is undermine the political transition, the national dialogue, which is fully supported by all the international community," Lyall Grant said.
"What we are saying is that we are giving our full weight behind that process, and we will not tolerate individuals of whatever stature undermining that process."
The council statement also expressed concern about reports "of money and weapons being brought into Yemen from outside for the purpose of undermining the transition".
Last week, Yemen asked the council to investigate a ship that Yemeni authorities said they seized with a cargo of Iranian-made bomb-making material, suicide belts, explosives, Katyusha rockets, surface-to-air missiles, rocket- ropelled grenades and large amounts of ammunition.
Hadi had previously sent a message to his Iranian counterpart, Mahmoud Ahmadinejad, calling on him to stop sending arms to Yemen and quit supporting a southern separatist movement.
Lyall Grant said the Security Council has asked the committee monitoring sanctions against Iran to investigate the weapons seizure.
The council statement reiterated the need for the transition to be "underpinned by a commitment to democracy, good governance, rule of law, national reconciliation and respect for the human rights and fundamental freedoms of all people in Yemen".
It urged the government to pass legislation on transitional justice to support reconciliation without delay.
The council emphasized the need for all segments of Yemeni society to be included in the national dialogue conference.
It called on all parties to honour the benchmarks and timetable in the transition agreement which call for the national dialogue to lead to a constitutional referendum and elections by February 2014.