President Donald Trump has named Lt. Gen. H.R. McMaster his new national security adviser, replacing Michael Flynn, who was suddenly forced to resign last week.

Trump also revealed that John Bolton, who served as ambassador to the United Nations under President George W. Bush, will be asked to serve the administration in an unspecified capacity.

The President made the announcement Monday from his Mar-a-Lago residence in Florida, joined by McMaster and retired Lt. Gen. Keith Kellogg. Kellogg had been serving as the acting national security adviser, and will now return to his role as chief of staff of the National Security Council.

In the announcement, Trump called McMaster a “man of tremendous talent and tremendous experience.” “I watched and read a lot over the last two days,” he said. “He is highly respected by everybody in the military, and we’re very honored to have him.”

McMaster, a career Army officer and strategist, will head the White House’s National Security Council, and become a top foreign policy adviser to Trump. He was not, however, Trump’s first choice for the job. POTUS had first offered the job Vice Adm. Robert Harward, who reportedly turned it down due to concerns over how the administration is being run, according to CNN.

“I would just like to say what a privilege it is to be able to continue serving our nation,” McMaster said in his appearance with Trump. “I’m grateful to you for that opportunity, and I look forward to joining the national security team and doing everything that I can to advance and protect the interests of the American people.”

Flynn was dismissed from the post after a report revealed that he had not disclosed to Vice President Mike Pence a conversation he had about sanctions with Russia’s ambassador to the U.S. before the Trump administration took office. Trump said that he fired Flynn not over the details of the conversation, but because of Flynn’s failure to disclose the conversation to Pence.

According to a White House spokeswoman, Sarah Huckabee Sanders,  Trump “gave full authority for McMaster to hire whatever staff he sees fit.”