WASHINGTON – A top communications aide to President Trump is exiting the White House as the embattled president considers a broader shake-up amid rising anxiety over investigations into his campaign’s contacts with Russia.

Fresh off Trump’s first official trip abroad, White House communications director Michael Dubke announced his resignation Tuesday in what many inside and outside the White House see as the first shoe to drop. A wider overhaul is expected, aimed at more aggressively responding to allegations of Russian meddling in the 2016 election and revelations of possible ties between Trump’s campaign and Moscow.

Dubke said in a statement it had been an honor to serve Trump and “my distinct pleasure to work side by side, day by day with the staff of the communications and press departments.”

However, Trump has privately and publicly pinned much of the blame for his administration’s woes on the communications effort.

“In terms of messaging, I would give myself a C or a C plus,” Trump said in an interview on Fox News Channel early in his term. “In terms of achievement, I think I’d give myself an A. Because I think I’ve done great things, but I don’t think I have – I and my people, I don’t think we’ve explained it well enough to the American public.”

Trump has long believed that he is his most effective spokesperson and has groused about supporters and aides not defending him vigorously enough. At the same time, he often undermines his staffers, contradicting their public statements and derailing their efforts to stay on topic with inflammatory tweets.

White House spokesman Sean Spicer pushed back Tuesday on the idea that a broader reorganization was imminent, but he acknowledged the president is frustrated with news stories “that are absolutely false, that are not based in fact. That is troubling.”

Spicer said he thinks the president “is very pleased with his team,” but he added, “Ultimately the best messenger is the president himself. He’s always proven that.”

Rumors of impending shake-ups have come and gone in the Trump White House before. But numerous people close to the president and his team are expecting further changes this time.

For example, Trump has entertained bringing his former campaign manager, Corey Lewandowski, and former deputy campaign manager, David Bossie, more formally back into the fold. Both Lewandowski and Bossie visited the White House on Monday night, according to two people familiar with the meeting, who spoke on condition of anonymity to discuss a private get-together.

But it remains unclear whether the president might envision them working inside the White House or in outside roles.

Bossie told “Fox & Friends” that the administration has reached out to him but hasn’t offered him a job.

“They have talked to many people, including me,” Bossie said. He later added: “It’s an ongoing conversation, and that’s a fair way to put it.”

Another person whose name has been raised as a possible addition to the president’s team is David Urban, a prominent Republican lobbyist, who also spent time advising Trump’s campaign and has remained a trusted adviser.

While overseas, Trump’s longtime lawyer, Marc Kasowitz, joined a still-forming legal team to help the president shoulder the intensifying investigations into Russian interference in the election and Trump associates’ potential involvement. More attorneys with deep experience in Washington investigations are expected to be added in the weeks ahead.

The latest revelations to emerge last week involved Trump’s son-in-law and top aide, Jared Kushner. Shortly after the election, Kushner is reported to have discussed setting up a secret communications channel with the Russian government to facilitate sensitive discussions about the conflict in Syria.

The intent was to connect Trump’s chief national security adviser at the time, Michael Flynn, with Russian military leaders, a person familiar with the discussions told the AP. The person wasn’t authorized to publicly discuss private policy deliberations and insisted on anonymity.

Flynn handed in his resignation in February, ousted on grounds that he had misled top White House officials about his contacts with Russian officials.

A senior administration official said Kushner was keeping his head down and focusing on work after the foreign trip. The official said Kushner was eager to share what he knows with Congress and other investigators. The official was not authorized to publicly discuss private thinking and spoke on the condition of anonymity.

Trump aides had been hoping to get through the trip before making staffing decisions.

Indeed, Dubke offered his resignation before the president’s departure, White House counselor Kellyanne Conway told The Associated Press, but offered to stay on during the trip. His last day has not yet been determined.

White House chief of staff Reince Priebus thanked Dubke in a statement and said he had “offered to remain onboard until a transition is concluded.”

“Mike will assist with the transition and be a strong advocate for the president and the president’s policies moving forward,” Priebus said.

Associated Press writers Vivian Salama, Ken Thomas and Julie Bykowicz contributed to this report.