WASHINGTON: Republican reservations have deepened about whether UN envoy Susan Rice should be nominated as US secretary of state, with senators demanding more answers about her role in the Benghazi affair.    

The embattled Rice met on Wednesday for a second straight day with her critics in the US Senate to try to mollify conservatives threatening to block her  confirmation if President Barack Obama picks her to replace Hillary Clinton.    

But moderate Senator Susan Collins joined other Republicans who have sharply criticised Rice for portraying the Sept.11 attack on the US mission in Libya as stemming from a protest against an anti-Islam film.    

“I still have many questions that remain unanswered,” said Collins after her hour-long meeting with Rice.     “I continue to be troubled by the fact that the UN ambassador decided to play a political role at the height of a contentious presidential election  campaign by agreeing to go on the Sunday shows to present the administration’s  position,” she said.

Rice met separately Senator Bob Corker, a Republican from Tennessee who expressed outrage at the US administration’s actions before and after what  he described as a “tawdry affair.”    

“I could not be more upset with our nation’s handling of Benghazi,” he said after his 90-minute meeting with Rice and acting Central Intelligence Agency (CIA) director Michael Morell. 

Rice steered clear of reporters for a second straight day but later attended Obama’s first cabinet meeting since he won re—election, and got a  vote of confidence from her boss.    

“Susan Rice is extraordinary. I couldn’t be prouder of the job she has done,” Obama said, before joining the cabinet in a round of applause for his UN  ambassador.    

Using talking points provided by the CIA, Rice said  it was the government’s “best assessment” that the assault appeared to have  started with a “spontaneous” reaction against an amateur anti-Muslim video.    

Collins acknowledged that Rice “made those conflicting assertions (when) there was conflicting evidence, that is true.”

But the senator said that others, including Libya’s de facto head-of-state Mohamed Al Megaryef, knew  early on that the attack was a pre-meditated act of terror.