The friendship with the Petraeus began when they arrived in Tampa, and the Kelleys threw a welcome party at their home, a short distance from Central Command headquarters, introducing the new chief and his wife, Holly, to Tampa’s elite, according to staffers who served with Petraeus.

Such friendships among senior military commanders and prominent local community leaders are common at any base, a relationship where the officers invite local people to exclusive military events and functions, and the invitees respond by providing private funding to support troops with everything from morale-boosting ‘‘Welcome Home’’ parades to assistance for injured combat veterans.

Petraeus aides say Jill Kelley took it to another level, winning the title of ‘‘honorary ambassador’’ from the countries involved in the Afghan war for her extensive entertaining at her home on behalf of the command, throwing parties that raised her social status in Tampa through the reflected glow of the four-star general in attendance.

Petraeus even honored Kelley and her husband with an award given to them in a special ceremony at the Pentagon just before he left the military for his post at the CIA, an aide said, speaking on condition of anonymity because he was not authorized to comment on the matter publicly.

White House spokesman Jay Carney, employing understatement, was asked about the revelations involving Allen and said Obama ‘‘wouldn’t call it welcome’’ news. Carney described Obama as ‘‘surprised’’ by the earlier news about Petraeus.

As he prepares for a second term, the president has hoped to run a methodical transition process, with the goal of keeping many Cabinet members and other high-ranking officials in their posts until successors are confirmed, or at least nominated. Petraeus’ resignation has disrupted those plans, leaving Obama with an immediate vacancy to fill and raising questions about how much other immediate shake-up the national security team can handle.

National Security Council spokesman Tommy Vietor said Obama put Allen’s nomination on hold at the request of Panetta. The general succeeded Petraeus as the top American commander in Afghanistan in July 2011 and has been working with Panetta on how best to pace the withdrawal of U.S. troops.

Vietor said in a written statement that Obama ‘‘remains focused on fully supporting our extraordinary troops and coalition partners in Afghanistan, who Gen. Allen continues to lead as he has so ably done for over a year.’’

The unfolding story caused a commotion on Capitol Hill as well, as lawmakers complained that they should have been told about the investigation earlier.

Rep. Peter King, R-N.Y., chairman of the House Homeland Security Committee, called the latest revelations ‘‘a Greek tragedy.’’

Acting CIA Director Michael Morell met with Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., and ranking Republican Saxby Chambliss of Georgia on Tuesday, to explain the CIA’s understanding of events that led Petraeus to resign. That session came ahead of meetings with the leaders of the House Intelligence Committee on Wednesday, according to congressional aides.

The chairman and top Republican on the Senate Armed Services Committee said their panel would go ahead with Thursday’s scheduled confirmation hearing on the nomination of Marine Corps Gen. Joseph Dunford, who is to replace Allen as commander of U.S. and NATO forces in Afghanistan, if Allen is indeed promoted.

Even though Petraeus has stepped down, Sen. Carl Levin, chairman of the Armed Services Committee, said the retired general should testify about the Sept. 11 attack on the U.S. Consulate in Benghazi, Libya, ‘‘if he has relevant information.’’ Sen. Susan Collins, R-Maine, said it was ‘‘absolutely imperative’’ that Petraeus testify, since he was CIA director during the attack and visited Libya afterward.

Asked by reporters if there was a national security breach with the Petraeus affair, Feinstein said: ‘‘We’re going to hold an inquiry. We’re going to look at things. I have no evidence that there was at this time.’’ She said she expected Petraeus to testify — ‘‘if not this week, then another week. That’s for sure.’’

Feinstein said did not believe that either Allen or Petraeus would release classified information.