CLEVELAND, OH - JULY 18: Retired Lt. Gen. Michael Flynn delivers a speech on the first day of the Republican National Convention on July 18, 2016 at the Quicken Loans Arena in Cleveland, Ohio. An estimated 50,000 people are expected in Cleveland, including hundreds of protesters and members of the media. The four-day Republican National Convention kicks off on July 18. (credit: Alex Wong/Getty Images)

Follow CBSDFW.COM: Facebook | Twitter

WASHINGTON (CBSDFW.COM/AP) – National Security Adviser Michael Flynn resigned late Monday night.

Flynn was on the job for less than a month.

The Acting National Security Advisor will be Joseph Kellogg according to the White House.

The White House released a statement saying:

General Kellogg is a decorated veteran of the United States Army, having served from 1967 to 2003, including two tours during the Vietnam War, where he earned the Silver Star, the Bronze Star with “V” device, and the Air Medal with “V” device. He served as the Commander of the 82nd Airborne Division from 1997 to 1998. Prior to his retirement, General Kellogg was Director of the Command, Control, Communications, and Computers Directorate under the Joint Chiefs of Staff.

This is the full text of General Flynn’s resignation letter released by the White House:

February 13, 2017

In the course of my duties as the incoming National Security Advisor, I held numerous phone calls with foreign counterparts, ministers, and ambassadors. These calls were to facilitate a smooth transition and begin to build the necessary relationships between the President, his advisors and foreign leaders. Such calls are standard practice in any transition of this magnitude.

Unfortunately, because of the fast pace of events, I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador. I have sincerely apologized to the President and the Vice President, and they have accepted my apology.

Throughout my over thirty three years of honorable military service, and my tenure as the National Security Advisor, I have always performed my duties with the utmost of integrity and honesty to those I have served, to include the President of the United States.

I am tendering my resignation, honored to have served our nation and the American people in such a distinguished way.

I am also extremely honored to have served President Trump, who in just three weeks, has reoriented American foreign policy in fundamental ways to restore America’s leadership position in the world.

As I step away once again from serving my nation in this current capacity, I wish to thank President Trump for his personal loyalty, the friendship of those who I worked with throughout the hard fought campaign, the challenging period of transition, and during the early days of his presidency.

I know with the strong leadership of President Donald J. Trump and Vice President Mike Pence and the superb team they are assembling, this team will go down in history as one of the greatest presidencies in U.S. history, and I firmly believe the American people will be well served as they all work together to help Make America Great Again.

Michael T. Flynn, LTG (Ret)

Assistant to the President / National Security Advisor

President Donald Trump, who spent the weekend at his private club in Florida, has yet to comment on Flynn’s status. Nor has Vice President Mike Pence, who previously denied that Flynn had discussed sanctions with Sergey Kislyak, the Russian ambassador to the U.S. Pence and Flynn spoke twice on Friday, according to an administration official.

Trump had told associates he is troubled by the situation, but had not said whether he planned to ask Flynn to step down, according to a person who spoke with him recently. Flynn was a loyal Trump supporter during the campaign, but he was viewed skeptically by some in the administration’s national security circles, in part because of his ties to Russia.

The administration official and both people with ties to Trump spoke on the condition of anonymity to discuss private conversations.

Stephen Miller, Trump’s top policy adviser, skirted the issue on several Sunday news shows, saying it was not his place to weigh in on the “sensitive matter” or to say whether the president retains confidence in Flynn.

(©2017 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)