Former New York City mayor Rudy Giuliani has formally withdrawn from consideration for a post in President-elect Donald Trump's administration.
It puts an end to his ill-fated bid to lead the State Department and leaves Mr Trump seriously considering Exxon Mobil chief executive Rex Tillerson for the post.
Mr Giuliani's prospects to serve as secretary of state had already dimmed, in part because of questions about his overseas business ties.
The former mayor said he removed himself from consideration on November 29.
"The whole thing was becoming kind of very confusing and very difficult for the president-elect," he said on Fox News. "My desire to be in the cabinet was great, but not that great."
Mr Trump said he would have been an "outstanding member of the cabinet in several roles".
Mitt Romney, the 2012 GOP presidential candidate, is also still in the mix.
The deliberations have divided Mr Trump's senior advisers, with some bluntly warning in public that including Mr Romney would anger the president-elect's loyal supporters.
He has sent mixed messages about him in recent days, suggesting in some conversations that Mr Romney is not getting the job and in others that he is still in contention.
Mr Trump is said to be intrigued by the prospect of filling the diplomatic post with an international businessman and has told those close to him that he likes the idea of an impressive-looking cabinet stocked with generals, the business elite and the extremely successful.
While he is said to be enamored with how Mr Romney looks the part of a statesman, he also reportedly likes the way Mr Tillerson projects success and gravitas from running a massive global corporation.
Mr Tillerson has led Exxon since 2006, a period when record high oil prices and record corporate profits helped make it the most valuable public company in the world.
He rose to prominence through the company's Russian energy business and was awarded Russia's Order of Friendship last year.
Mr Giuliani, a loyal supporter throughout the presidential race, quickly emerged as a top contender for secretary of state.
But his financial ties, as well as his frequent public campaigning for the job, are said to have given Mr Trump pause.
Those close to the president-elect said he had concerns that the 72-year-old may lack the stamina and charisma for the high-profile, globe-trotting position.
After leaving the government, Mr Giuliani advised foreign political figures and worked for lobbying and security firms whose clients have had complicated relationships with the US government.
While not personally involved in lobbying, he spent years at firms that represented governments and multinational companies. He also made speeches demanding the State Department remove an Iranian opposition group from a US terror blacklist.
Incoming White House chief of staff Reince Priebus, who is seen inside the transition team as favoring Mr Romney, said the former mayor was vetted for possible conflicts and "passed with flying colours".
Kellyanne Conway, Mr Trump's senior advisor, said Mr Giuliani's decision to remove himself from consideration was a "mutual decision" with the president-elect.
She has been an outspoken critic of Mr Romney, publicly warning Mr Trump that his supporters would feel betrayed if he uses the 2012 Republican nominee for the prominent and powerful Cabinet post.
Mr Romney had blasted Mr Trump as a "fraud" who was playing the American public "for suckers".
But he emerged from a private dinner with the president-elect last week - their second meeting since the election - full of praise for the president-elect.
Still, Mr Trump moved to expand his pool of contenders. He met Mr Tillerson in New York this week and has had discussions with Tennessee senator Bob Corker and John Bolton, the former US ambassador to the United Nations.
Some advisers had hoped Mr Giuliani would be interested in being nominated for secretary of Homeland Security, where they believed his financial ties would not cause as much concern. But he made clear he was only interested in the diplomatic post.
The announcement means several of Mr Trump's most ardent campaign supporters will not be joining his administration.
Former House Speaker Newt Gingrich has said he does not plan to have a formal role. New Jersey governor Chris Christie, initially seen as a contender, is expected to be left empty-handed.