WASHINGTON, June 19 (Xinhua) -- U.S. Secretary of the Army Mark Esper, who will replace Patrick Shanahan as acting defense secretary Monday, will attend the NATO defense ministerial meeting in Brussels at the end of June, the Pentagon announced Wednesday.

In this April 2, 2019, file photo, Secretary of the Army Mark Esper speaks during a House Armed Services Committee budget hearing on Capitol Hill in Washington. (Photo: AP)

Acting Secretary of Defense Patrick Shanahan will step down Sunday, handing Esper the reins to the Pentagon. Esper's travel to NATO headquarters in Belgium will be his first overseas trip as acting chief of Pentagon.

"The focus of his meetings will be reinforcing the U.S. commitment to strengthening the NATO Alliance, ensuring more equitable burden sharing, bolstering NATO readiness and addressing regional security issues,"the Pentagon said in a statement.

The transition of power came after U.S. President Donald Trump said Shanahan had withdrawn his nomination as the secretary of defense, citing family issues. Trump tweeted that he will appoint Esper to be the acting defense chief.

Esper, who graduated from West Point and served in the U.S. Army during the Gulf War, saw his career span across think tanks, the executive branch and the U.S. Congress. He was hired by defense contractor Raytheon in 2010. Esper assumed his current role in November 2017.