Veteran White House reporter Helen Thomas accepts cupcakes from U.S. President Barack Obama in August, marking Thomas's 89th birthday and Obama's 48th. (J. Scott Applewhite/Associated Press) Helen Thomas, who has covered the White House since the days of U.S. President John F. Kennedy, will retire immediately, her employer announced on Monday amid a brewing scandal over recent remarks the veteran Washington journalist made about Israel.

Because of her lengthy tenure, the 89-year-old Thomas — who became a columnist for Hearst Newspapers after leaving her longtime employer United Press International in 2000 — had held the privilege of closing all presidential press conferences with the words "Thank you, Mr. President."

She did not attend Monday's daily press briefing, at which White House press secretary Robert Gibbs criticized her remarks as "offensive and reprehensible."

At an event celebrating Jewish heritage at the White House on May 27, Thomas was captured on video remarking that Jews in Israel should "get the hell out of Palestine" and "go back to Poland, Germany, America and everywhere else."

The video, which was posted to the website RabbiLive.com and quickly spread online, and her comments have been blasted by a host of groups, including the Anti-Defamation League and the White House Correspondents' Association.

Helen Thomas, seen at the White House briefing room in 2008, has covered every U.S. president since John F. Kennedy. (Alex Wong/Getty Images)On the weekend, Walt Whitman High School — located in a suburb of Washington — also cancelled the speech Thomas was scheduled to deliver at its upcoming graduation ceremony because of the remarks.

Thomas, who has previously courted controversy for her confrontational questioning, apologized for her remarks on Friday.

"I deeply regret my comments I made last week regarding the Israelis and the Palestinians," Thomas wrote on her website.

"They do not reflect my heartfelt belief that peace will come to the Middle East only when all parties recognize the need for mutual respect and tolerance. May that day come soon."

The Kentucky-born Thomas began her journalism career in the 1940s. A trailblazer for female journalists, she was the first female officer of the National Press Club as well as the first female member and first female president of the White House Correspondents Association.

She had often been referred to as "the dean of the White House press corps."

With files from The Associated Press