WASHINGTON — Leaders from the country’s largest veterans groups on Wednesday held a private event to honor fired Veterans Affairs Secretary David Shulkin, indicating a growing rift between the administration and some of the most prominent advocates for the veterans community.

The event, held at the Disabled American Veterans headquarters in town, was a chance for the groups to thank Shulkin for his 13 months leading the department and praise his “bipartisan” approach to the job.

The evening ceremony also honored Shulkin’s former chief of staff, Vivieca Wright Simpson, who abruptly retired in February amid allegations she doctored internal emails so the department would pay for Shulkin’s wife to accompany him on an overseas trip last summer. Veterans groups praised her 32 years of work in VA, much of it interacting with them.

Shulkin’s remarks at the event were more cordial that others he has given since President Donald Trump dismissed him over Twitter last month. White House officials said his handling of the travel scandal had become a distraction, but Shulkin in numerous media appearances has said he was forced out of office by political operatives working to privatize veterans health care.

The former secretary made no mention of the issue in his brief remarks, instead saying only that he plans to continue being an advocate on veterans issues.

“I know that you in this room and our leadership is going to do the right thing for veterans,” he said. “We will continue to make progress and continue to honor our veterans.”

Wednesday’s celebration of Shulkin, which was not open to the press, included key leaders from each of the “big six” veterans groups — American Legion, AMVETS, DAV, Paralyzed Veterans of America, Veterans of Foreign Wars and Vietnam Veterans of America — as well as several other organizations.

Despite a host of legislative victories last year, the relationship between those groups and the White House have been strained in recent months.

Many of the veterans groups present at the event have been vocal in their disappointment over Shulkin’s firing, and their concerns that forces within the administration are advocating too aggressive policies for expanding private-care medical appointments for veterans.

Several have openly objected to Trump’s decision to include Concerned Veterans for America — which has close ties to the conservative Koch brothers’ network — in high-level policy meetings at the White House. Shulkin has blamed affiliates of the group for his ouster.

Last week, officials from AMVETS demanded Trump remove acting VA Secretary Robert Wilkie from the post and elevate VA Deputy Secretary Thomas Bowman instead, citing potential legal issues with ignoring the department’s chain of command.

Bowman has also been a target of Shulkin’s critics. Both he and Wright Simpson were seen by some White House insiders as obstacles to Trump administration reform efforts, due to their longtime ties to Congress and the department bureaucracy, respectively.

Veterans policy was a positive and largely uncontroversial issue for the Trump administration for most of 2017, but it has become an increasingly politicized topic since the Shulkin travel scandal emerged.

The prospect of a broader fight between top advocates and administration officials could produce more political challenges for a department whose leader has been forced out of office twice in the last four years.

Senate Veterans’ Affairs Committee Chairman Johnny Isakson, R-Ga., House Veterans’ Affairs Committee Chairman Phil Roe, R-Tenn., and Senate Veterans’ Affairs Committee Chairman ranking member Jon Tester, D-Mont., also attended the Shulkin event, although their offices were not involved in the planning.

Nearly two-thirds of veterans who voted in the 2016 presidential election backed Trump. Critics of the veterans groups have accused them of being out-of-touch with membership concerns, and of working to maintain current VA systems instead of backing Trump’s proposed reforms.