UPDATE - Trump to nominate acting secretary as Pentagon chief

ADDS DETAILS THROUGHOUT

By Michael Hernandez

WASHINGTON (AA) – U.S. President Donald Trump will nominate acting Secretary of Defense Patrick Shanahan to be defense secretary, the White House announced Thursday.

"Acting Secretary Shanahan has proven over the last several months that he is beyond qualified to lead the Department of Defense, and he will continue to do an excellent job,” spokeswoman Sarah Sanders said in a statement announcing the president's intent.

The top Pentagon post has been vacant since former Defense Secretary James Mattis resigned in December over disagreements with the president, including his abrupt decision to withdraw U.S. forces from Syria.

Mattis had originally said his resignation would be effective in February, but angered by the retired Marine Corps general's critical resignation letter, Trump made it effective at the start of January.

Shanahan has been acting in the interim as the Pentagon's top official.

The former Boeing executive will have to face Senate confirmation after Trump officially makes the nomination.

"If confirmed by the Senate, I will continue the aggressive implementation of our National Defense Strategy," Shanahan said in a statement. "I remain committed to modernizing the force so our remarkable Soldiers, Sailors, Airmen, and Marines have everything they need to keep our military lethal and our country safe."

Shanahan, 56, had been Boeing's top supply chain executive prior to joining the Department of Defense in 2017 as deputy secretary of defense.

He will have to helm the Department of Defense as the administration finds itself in the thick of difficulties with North Korea, Venezuela and Iran.

Those challenges are compounded by the Pentagon's assessment that Russia and China are steadily narrowing the U.S.'s military lead, a fact alluded to in Shanahan's statement.