* Republican senators threaten to block any Rice nomination
* Democrat Feinstein says Petraeus willing to testify
By Tabassum Zakaria and Susan Cornwell
WASHINGTON, Nov 14 (Reuters) - President Barack Obama told Republican senators on Wednesday if they had a problem with the handling of the Benghazi attack in Libya to "go after me" rather than pick on his ambassador to the United Nations, Susan Rice.
Obama's comments, in a combative tone, came after two senior Republican senators said they would block any attempts by the president to put Rice into a Cabinet position that would require Senate confirmation.
Republicans have criticized Rice for going on a round of Sunday talk shows five days after the Sept. 11 attack on the U.S. diplomatic mission in Benghazi, Libya, and saying that preliminary information suggested it was the result of protests over an anti-Muslim film rather than a premeditated strike.
The White House has repeatedly said the comments were based on the best information Rice had at the time. But Republicans have used her early assessment as a cudgel for criticizing the administration as not being forthcoming about Benghazi, and the senators' remarks Wednesday suggested they would pursue the issue even though the U.S. presidential election is over.
"But for them to go after the U.N. ambassador who had nothing to do with Benghazi, and was simply making a presentation based on intelligence that she had received, and to besmirch her reputation is outrageous," Obama said.
The U.S. ambassador to Libya and three other Americans were killed in the attack that has raised questions about the security of the diplomatic mission, U.S. intelligence about the threat, and the adequacy of the immediate U.S. response.
The issue has gained post-election sensitivity for the administration as Obama shapes his Cabinet for a second term. Rice is considered a possible contender to replace Secretary of State Hillary Clinton who does not intend to stay, or for another top post.
"We will do whatever's necessary to block the nomination that's within our power as far as Susan Rice is concerned," said Republican Senator John McCain, who was joined by fellow Republican Senator Lindsey Graham.
At his first news conference since being re-elected, Obama retorted: "If Senator McCain and Senator Graham, and others want to go after somebody, they should go after me. And I'm happy to have that discussion with them."
Obama said he had not made decisions on his second-term Cabinet yet but if he decided that Rice would be the best person to lead the State Department, "then I will nominate her."
Asked why, if Rice had nothing to do with Benghazi she was sent on the talk shows to give the administration's point of view, White House spokesman Tommy Vietor told Reuters: "It made sense to have Ambassador Rice, one of our most senior diplomats, speak about the critical work our diplomats do every day. Ambassador Rice was also uniquely qualified to speak about the broader unrest in the region at the time."
The Senate and House intelligence committees have scheduled separate closed-door hearings on Thursday about Benghazi. Former CIA Director David Petraeus had initially been scheduled to testify but after his resignation on Friday over an extramarital affair, acting CIA Director Michael Morell will take his place.
Senate Intelligence Committee Chairman Dianne Feinstein has been adamant that Petraeus should still testify about the Benghazi attacks since he was head of CIA when it happened and on Wednesday said it was likely that he would at some point, although the timing was unclear.
"He is very willing and interested in talking to the committee," Feinstein told reporters.
The administration's response to Benghazi became a key issue in the last months of the presidential campaign and Obama said at the news conference that he wanted to get to the bottom of what happened.
"I think it is important for us to find out exactly what happened in Benghazi and I'm happy to cooperate in any ways that Congress wants," he said.
"And we've got to get to the bottom of it and there needs to be accountability. We've got to bring those who carried it out to justice. They won't get any debate from me on that," he said.
McCain and Graham called for the creation of a Senate special committee to investigate the Benghazi attack, rather than have three separate committees with jurisdiction hold hearings: intelligence, armed services and foreign relations.
"Why did senior administration officials seek to blame the spontaneous demonstration for the attack in Benghazi when it was later acknowledged that no protests even occurred in Benghazi and that the (CIA) station chief in Tripoli was apparently reporting back in the first 24 hours that it was a terrorist attack?" McCain said.
But there appeared to be little support among Democrats who control the Senate - or even among some Republicans - for creating a special committee to investigate the Benghazi events.
House Speaker John Boehner, who like McCain is a Republican, said at this point he did not favor creating a special committee to investigate the events in Benghazi.
When asked if he would support the idea, Senate Majority Leader Harry Reid, a Democrat, bluntly said "no."