WASHINGTON (Reuters) - Republican senators who met with U.S. Ambassador to the United Nations Susan Rice on Tuesday said they would not support any nomination of her to a higher post until questions about the administration's response to the attack on the U.S. mission in Benghazi, Libya, were answered.

Senators John McCain, Lindsey Graham and Kelly Ayotte met behind closed doors with Rice for about an hour and said they were still troubled by her responses to their questions about her early comments following the September 11, 2012, attack that killed the U.S. ambassador to Libya and three other Americans.

Rice is considered a possible contender for secretary of state in President Barack Obama's second term, a position that would require Senate confirmation.

(Reporting By Tabassum Zakaria; Editing by Eric Beech)