The trip, scheduled for the middle of this month, had not yet been publicly announced; but word that it had been postponed leaked to the media so Pentagon officials opted to publicly acknowledge that the trip had been scrubbed for now. Pentagon Press Secretary Rear Adm. John Kirby told reporters at the Pentagon Tuesday that the likelihood of pop-up congressional hearings this month and other meetings drove the decision to postpone – not cancel – the trip.

“In light of the likelihood — at least, we know of one, and maybe the likelihood of more congressional hearings in the next couple of weeks, it was deemed the most prudent thing to do to make sure that he was available to answer questions from Congress about any number of matters that are on their minds,” Kirby said.

Congressional hearings are usually scheduled weeks or months in advance and don’t typically interfere with official travel in this way. When they do, the Pentagon usually sends someone in the secretary’s place – say, the Deputy Secretary of Defense or the Under Secretary of Defense for Policy – the Pentagon’s No. 2 and No. 3, respectively.

While the Pentagon changes travel plans all the time, once a trip is scheduled, it is more or less set in stone. The postponement of Hagel’s Asia trip indicates that whatever is keeping him in Washington is particularly important.

Hagel has defined his job as secretary as shepherding the so-called Asia pivot through the defense bureaucracy and keeping the concept alive amid crises in Ukraine, the Middle East and Africa. The trip to Vietnam would have been his seventh trip to the region since February 2013 and his first, as secretary, to Vietnam where he fought in the war. Crises in other parts of the world have dominated many of Hagel’s trips to Asia.

Amid the worsening situation in Iraq, the optics of Hagel traveling to Asia once again, and with few tangible deliveries, would not help the administration as it tries to make it look as if it is singularly focused on the problems in the Middle East.

And after Tuesday’s mid-term elections are complete, Republican members of Congress, some of whom may be emboldened by the election’s results, are likely to demand more answers on the Obama administration’s policies.

At the same time, Hagel, along with other members of Obama’s national security team, has been under scrutiny amid mounting concerns that the White House’s foreign policy has not been effective. There have been some media reports that hint that Obama may be thinking about a shake-up of his national security team that could include Hagel, Secretary of State John Kerry or National Security Adviser Susan Rice.

But while Hagel has not been seen as a stand-out in this realm, he has quietly been pushing for a more aggressive policy in Syria and perhaps Iraq as well and administration officials insist Hagel has been doing a good job.

Still, the postponed trip raised questions of whether there were other issues, not just congressional testimony, that would keep Hagel home.

“The secretary enjoys a very close relationship with the president and the national security staff,” Kirby said.

Hagel “is extremely and strongly committed to the [Asia] rebalance, and he understands the ramifications of not being able to go,” he added.