WASHINGTON — The Latest on Defense Secretary Jim Mattis (all times local):

1:45 p.m.

The nation’s top military officer says the thousands of additional U.S. troops President Donald Trump has ordered to Afghanistan will cost just over $1 billion a year.

Marine Corps Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, says the U.S. is spending $12.5 billion overall to wage America’s longest war.

Dunford and Defense Secretary Jim Mattis are testifying before congressional committees Tuesday.

About 3,500 more American forces are being sent to Afghanistan as part of Trump’s new strategy. Dunford says the U.S. will “fight to win” by attacking enemies, “crushing” al-Qaida, and preventing terrorist attacks against Americans. The additional troops will augment the roughly 8,400 Americans currently stationed there.

Dunford says about $5 billion of the total expense is required to support the Afghan security forces.


12:10 p.m.

Defense Secretary Jim Mattis says the United States should remain in the nuclear deal negotiated during the Obama administration that constrains Iran’s ability to build a nuclear arsenal.

Sen. Angus King of Maine asked Mattis during a congressional hearing if he thinks it’s in the national security interests of the United States to stay a part of the international accord.

Mattis says, “Yes, senator, I do.”

President Donald Trump has called the deal the worst agreement ever negotiated by the United States.

Trump has repeatedly said that he’s inclined not to certify Iranian compliance after having twice found the country compliant at earlier deadlines. Denying certification could lead the U.S. to reintroduce sanctions, which in turn could lead Iran to walk away from the deal or restart previously curtailed nuclear activities.


10:50 a.m.

Defense Secretary Jim Mattis says Afghanistan security forces are fully engaged in offensive military operations for the first time during the 16-year-old war.

During congressional testimony Tuesday, Mattis says the Afghan forces are suffering fewer casualties as they continue to improve.

Mattis says more than 3,000 additional U.S. troops are being sent to Afghanistan to reinforce the roughly 8,400 American forces currently stationed there.

President Donald Trump announced in August a plan to end America’s longest war and eliminate a rising extremist threat in Afghanistan.

Sen. John McCain of Arizona, the chairman of the Armed Services Committee, lectured Mattis and Gen. Joseph Dunford at the opening of the hearing. McCain says the Trump administration has failed to inform Congress of the details of the strategy spelled out by Trump.