Mark Esper was sworn in as secretary of defense Tuesday after being confirmed by the Senate, filling a Cabinet role that's been vacant since James Mattis' departure nearly seven months ago.

The Senate armed services committee opened a confirmation hearing Tuesday for acting Defense Secretary Mark Esper.

Lockheed Martin was awarded $348.2 million for Lot 12 low-rate initial production of the F-35, while Pratt & Whitney reportedly is working to correct issues causing it to be chronically late delivering engines for them.

President Donald Trump has announced his intention to nominate Mark Esper, secretary of the Army, as the next defense secretary, among other key defense posts.

Iran's Islamic Revolutionary Guards Corps said Thursday it shot down a U.S. military drone along the country's southern coast after it violated Iranian airspace, a claim rejected by the Pentagon.

Acting Defense Secretary Patrick Shanahan on Tuesday withdrew himself from consideration to be formally nominated to head the Defense Department, President Donald Trump announced.

The Pentagon on Monday announced it is sending 1,000 additional troops to the Middle East after attacks on oil tankers in the Gulf of Oman last week, which U.S. officials blamed on Iran.

The Pentagon's threat to remove Turkey from the F-35 program is not in line with the spirit of the two nation's alliance, the Middle East country's national defense minister said this week.

Acting Defense Secretary Patrick Shanahan has reminded all military personnel "that our mission, to protect and defend the nation, is apolitical."

Iran formally delivered a new surface-to-air missile defense system, called Khordad 15th, to its Air Defense Force in a ceremony in Tehran.

Turkey's involvement in manufacturing the F-35 fighter plane will end if it insists on buying a Russian air defense system.

An improvised explosive device damaged a U.S. tactical vehicle in western Niger, with no casualties reported by U.S. Africa Command.

Acting Defense Secretary Patrick Shanahan said there will be military-to-military conversation after the Russian destroyer Admiral Vinogradov came within 100 feet of the USS Chancellorsville Friday in the Philippine Sea.

No further disciplinary action will be taken against soldiers in response to ambushes in Niger two years ago that killed four Green Berets, acting Defense Secretary Patrick Shanahan said Thursday.

During U.S. President Donald Trump's four-day state visit to Japan, Prime Minister Shinzo Abe offered mediation between the United States and Iran amid rising tensions. Trump happily accepted the offer.