The United Nations Security Council imposed targeted sanctions on Friday on Yemen's former President Ali Abdullah Saleh and two senior Houthi rebel leaders for threatening the peace and stability of the country and obstructing the political process.

Lithuanian U.N. Ambassador Raimonda Murmokaite, chair of the council's Yemen sanctions committee, said all 15 members had agreed to blacklist Saleh and Houthi rebel military leaders Abd al-Khaliq al-Huthi and Abdullah Yahya al Hakim. The three men are now subject to a global travel ban and asset freeze.

Saleh has denied seeking to destabilize Yemen and his party warned after a meeting on Thursday that any sanctions on the former president or "even waving such a threat would have negative consequences on the political process."

The U.N. Security Council in February authorized sanctions against anyone in Yemen who obstructs the country's political transition or commits human rights violations, but stopped short of blacklisting any specific individuals.

The United States submitted a formal request to the Yemen sanctions committee a week ago for Saleh and the Houthi leaders to be the first people designated.

"With today's designations, members of the Security Council have made clear that the international community will not tolerate efforts to use violence to thwart the legitimate aspirations of the Yemeni people and their ongoing political transition," said a U.S. official, speaking on condition of anonymity.

Yemen, a U.S. ally that borders oil-producer Saudi Arabia, is trying to end political unrest that began with mass protests against Saleh, president for 33 years until he stepped down in 2012.

"As of fall 2012 Ali Abdullah Saleh had reportedly become one of the primary supporters of the Huthi rebellion. Saleh was behind the attempts to cause chaos throughout Yemen," the United States said in a "statement of case" obtained by Reuters.

"More recently, as of September 2014, Saleh is reportedly inciting instability in Yemen by using the Huthi dissident group to not only delegitimize the central government, but also create enough instability to stage a coup," it said.

Fighting has flared in different parts of Yemen since the Houthis, a group of Shi'ite Muslim rebels, rose to dominance in recent months, threatening the fragile stability of a country bordering on Saudi Arabia, the world's biggest oil exporter.

Houthi forces took over the capital, Sanaa, in September and fanned out into central and western Yemen. That antagonized Sunni tribesmen and al Qaeda militants, who regard the Houthis as heretics.

"In late September 2014, an unknown number of unidentified Huthi movement fighters allegedly were prepared to attack the U.S. Embassy in Sana'a, Yemen, upon receiving orders from Huthi military commander of Sana'a, Abd al-Khaliq al-Huthi," said the United States 'statement of case' against al-Huthi.

It said the role of al Hakim was to organize military operations "to be able to topple the Yemeni government" and that he was responsible for securing and controlling all routes in and out of Sanaa.