The United States said Saturday that it will directly oversee the implementation of a Gulf-brokered deal for the power transfer in Yemen, the Yemeni official news agency Saba reported.

"The Unites States will directly and closely oversee the implementation of the UN-backed Gulf Cooperation Council (GCC) initiative and its executive mechanism that agreed upon by the entire international community," the assistant to the U.S. president for counterterrorism, John Brennan, told Yemeni Vice President Abd-Rabbu Mansour Hadi in a phone conversation on Saturday evening.

The conversation was reported by Saba immediately following the declaration of Yemeni President Ali Abdullah Saleh's return from Riyadh three days after he signed the GCC deal.

"Brennan conveyed warm congratulations from U.S. President Barack Obama to Hadi on the signing of the GCC deal and the break of Yemeni political standoff, reaffirming that the United States will work along with its allies in Europe and the world to directly help Yemen to end its political, security and economic crises, as well as in combating terrorism," Saba said.

Saleh's return also came almost simultaneously with the issuance of a republican decree by Hadi, in which he declared Feb. 21, 2012 as the date for the early presidential elections in line with the GCC initiative.

The decree said that "no party has the right to annul or change the date."

Under the GCC deal, Saleh moved power to Hadi on Wednesday, in return for immunity from prosecution, which was rejected by some angry protester.

The deal stipulated the early presidential elections should be held in 90 days.

Government officials said that according to the GCC deal Saleh will retain the title of honorary president until a new leader is elected.

One of the official told Xinhua that "Saleh will take part in overseeing the implementation of the power-transfer deal."

Yemen has been rattled by 10 months of protests and unrest, which almost brought the impoverished Arab state to the verge of civil war and economic collapse.

Witnesses and residents in Yemen's southern restive province of Taiz said heavy clashes between the government troops and opposition armed tribesmen flared immediately after the state media announced Saleh's return to Sanaa. No casualty was reported yet.