WASHINGTON, Nov. 24 (Xinhua/Sun) -- U.S. President Barack Obama on Monday announced resignation of Chuck Hagel as the country's defense secretary, making the first change to his cabinet after the Democrats' heavy losses in both chambers of Congress in the midterm elections early this month.

During a statement delivered at the White House, Obama said Hagel concluded that now was an "appropriate time for him to complete his service."

The president also praised Hagel as an "exemplary defense secretary," commending Hagel for his "steady hand" through a period of transition for the U.S military.

Hagel, a 68-year-old Republican who took office in February 2013, said in a statement following Obama's announcement that he would stay on the job until his successor is nominated and confirmed by the Senate.

Analysts reckon that Obama's decision on Hagel's removal appears to be an effort by the White House to show that it is sensitive to critics who have pointed to stumbles in the government's response to several national security issues, including the Ebola crisis and the threat posed by the Islamic State