Mike Dubke resigned from his role as the White House communications director. Credit Black Rock Group

WASHINGTON — Michael Dubke, the White House communications director, announced on Tuesday that he is resigning, as President Trump weighs a broader shake-up of his staff in the face of multiple investigations.

Mr. Dubke, a veteran Republican strategist who served three months in the role, said that he offered his resignation on May 18 and agreed to stay on until Mr. Trump completed his first overseas trip, which ended over the weekend. Other staff changes could come by the end of the week, White House officials said.

“The reasons for my departure are personal, but it has been my great honor to serve President Trump and this administration,” Mr. Dubke said in a message to friends. “It has also been my distinct pleasure to work side-by-side, day-by-day with the staff of the communications and press departments. This White House is filled with some of the finest and hardest working men and women in the American government.”

The president’s inner circle has been preparing a series of shifts intended to deal with the growing inquiries into any contacts between associates of Mr. Trump and Russia during last year’s presidential campaign and the transition before the inauguration.


A screenshot of an email that the White House communications director, Mike Dubke, sent to associates announcing his resignation from the Trump administration.

Among those who have been caught up in the probes is Jared Kushner, the president’s son-in-law and senior adviser, who reportedly explored the possibility of setting up a secret communications channel to Moscow.

A damage control plan assembled by the president’s aides would try to wall off the investigations by setting up a war room inside the White House and enlisting a high-powered team of lawyers outside the West Wing.

Corey Lewandowski, at one point Mr. Trump’s campaign manager last year, and David Bossie, who was deputy campaign manager, are in discussions about whether to come onto the White House staff to handle the political and communications response to the inquiries.

Sean Spicer, the White House press secretary, who has been the subject of much speculation, would stay on in this situation, but he might lead fewer on-camera daily briefings.

The challenges for any communications adviser to Mr. Trump were on display Tuesday morning as the president returned to Twitter with more provocative messages challenging Germany and Democrats.

“We have a MASSIVE trade deficit with Germany, plus they pay FAR LESS than they should on NATO & military,” Mr. Trump wrote. “Very bad for U.S. This will change.”

He also repeated his contention that the Russia investigation was merely political distraction by Democrats seeking to discredit his Electoral College victory.

“Russian officials must be laughing at the U.S. & how a lame excuse for why the Dems lost the election has taken over the Fake News,” he wrote.

Advisers have cautioned Mr. Trump about his use of Twitter, with lawyers making the argument that every tweet can be evidence. Diplomats likewise have worried that his Twitter messages can disrupt relations with allies unnecessarily.

But Mr. Trump is resistant to advice from experienced political hands like Mr. Dubke and seemingly unable to allow any slight to go unanswered. Chancellor Angela Merkel of Germany said over the weekend that Europe could no longer rely on American leadership, a comment that evidently grated on the president.

Ms. Merkel’s remark and Mr. Trump’s reply reflected rising transatlantic tension following the president’s visit to Europe. At back-to-back meetings of leaders of the NATO alliance and the Group of 7 major powers, Mr. Trump was at odds with traditional European allies over trade, defense spending and the Paris climate change agreement.