Bloomberg has been heavily courted by both presidential campaigns in 2012, with political watchers saying the mayor's independent streak and fortune make him perhaps the most valuable up-for-grabs endorsement of the campaign.

Mitt Romney held a private breakfast meeting with the mayor during a campaign swing through Manhattan last month, and Sen. John McCainJohn Sidney McCainSenate's defense authorization would set cyber doctrine Senate Dems hold floor talk-a-thon against latest ObamaCare repeal bill Overnight Defense: Senate passes 0B defense bill | 3,000 US troops heading to Afghanistan | Two more Navy officials fired over ship collisions MORE (R-Ariz.) has lobbied Bloomberg on the GOP hopeful's behalf.

Earlier, Bloomberg played golf in Washington, D.C., with Vice President Biden and Defense Secretary Leon Panetta, according to The New York Times. The mayor was also a guest at a White House luncheon with Obama in April.

Bloomberg opted not to endorse in the 2008 election, although New York media sources have widely reported that he is considering weighing in this year. There have also been numerous reports that Bloomberg has been dissatisfied with the Obama administration, particularly objecting to the president's criticism of Wall Street executives. But the offer of the World Bank job, even rebuffed, might have served as an olive branch from the president.

The mayor was said to be considering his own presidential run earlier in the campaign cycle, but ultimately opted against what would be a difficult third-party bid for the White House.