(Updates with Kerry statement, paragraphs 4-7)
WASHINGTON, Feb 1 (Reuters) - U.S. President Barack Obama offered Senator John Kerry the job of secretary of state a week before Susan Rice, the U.S. ambassador to the United Nations, withdrew her name from contention, the Boston Globe reported on Friday.
"He called me, actually a week before Susan got out of the thing," Kerry told the newspaper, offering a timeline earlier than previously reported.
"He called me and said, 'You're my choice. I want you to do this.' He asked me to keep it quiet. I did. I sat on it," the newspaper quoted him as saying.
Kerry sought to clarify his remarks later on Friday.
"Private discussions are best kept private and my imprecise, overly casual answer to a question about timing confused things," Kerry, who was sworn in as secretary of state on Friday, said in a statement.
"To clarify, through many private conversations over a long and busy period for everyone, I knew that the President was interested in the possibility of my serving as Secretary of State but the President did not formally offer me the job until later in December," he said.
Kerry did not specify the date of Obama's offer.
Rice, a top aide to Obama during his 2008 presidential campaign, withdrew her name from consideration as secretary of state on Dec. 13 in the face of what promised to be a contentious Senate confirmation battle.
A spokesman for Kerry was not immediately available for comment on his reported remarks.
There has been widespread speculation that Kerry was Obama's second choice for the top diplomatic job. The White House has said Rice's decision to withdraw from contention was her own.
White House spokesman Jay Carney on Friday declined to comment on the newspaper report.
"I'm not going to get into private conversations between the president and ... a senator or a Cabinet member," he said.
Rice had drawn heavy fire from Republicans for remarks she made in the aftermath of the Sept. 11, 2012, attack on the U.S. mission in Benghazi, Libya, in which four Americans were killed, including Ambassador Chris Stevens.
"I am highly honored to be considered by you for appointment as secretary of state," Rice said in a letter to Obama released on Dec. 13. "I am fully confident that I could serve our country ably and effectively in that role. However, if nominated, I am now convinced that the confirmation process would be lengthy, disruptive and costly."
The U.S. Mission to the United Nations, where Rice works, had no immediate reaction to the Boston Globe report.
Kerry, a five-term U.S. senator from Massachusetts and the losing Democratic presidential candidate in 2004, was easily confirmed on Tuesday, with the Senate voting 94-3 in favor. (Reporting By Arshad Mohammed, additional reporting by Roberta Rampton in Washington and Lou Charbonneau at the United Nations; Editing by Warren Strobel, Xavier Briand and Eric Walsh)