WASHINGTON — Defense Secretary Ashton Carter said Thursday he will formally end the Pentagon’s ban on women serving in combat jobs, allowing them to join artillery, infantry and other frontline units for the first time next April.

“There will be no exceptions,” Carter said.

“This means that, as long as they qualify and meet the standards, women will now be able to contribute to our mission in ways they could not before.”

The decision is historic for the tradition-bound, male-dominated military, which has long resisted putting women into combat. Critics have argued that women lack the strength and agility to fight and survive in battlefield conditions, and that their presence could erode morale.

But Carter said that after a three-year military review, the chiefs of the Army, Navy, Air Force and Special Operations Command all had agreed to open all their combat positions to qualified women.

He said the Marine Corps had requested exemptions for some jobs, such as machine gunner, but he’d overruled the requests because the military is a joint force and should operate under a common set of standards.

Carter gave the armed services until Jan. 1 to submit plans to open combat jobs, and until April 1 to begin implementing the changes.

MANY SPECIALTIES NOW OPEN

Advocates long have sought an end to the Pentagon’s combat restrictions, which have prevented women from advancing in rank as quickly as men.

Despite the ban, thousands of women have served as drivers, pilots, analysts and other jobs with combat units in Iraq, Afghanistan and other war zones.

Hundreds have been wounded or killed. Two women received Silver Star medals, one in 2005 and another in 2008, for action in battle.

Carter’s decision follows a 2013 Pentagon order to end the long-standing ban on women in combat jobs by 2016 or justify specific exemptions.

Despite a steady easing of restrictions, about 10 percent of military specialties – about 220,000 categories in all – have been closed to women, including infantry, armor, artillery and some special operations units.

Those jobs will now open. For the first time, women who pass the rigorous training and testing will be able to join the Navy SEALs, Army Special Forces and other special operations units.

Carter’s decision was widely expected after several women passed the training this year that would allow them to qualify as Army Rangers, an elite unit.

Critics in Congress were quick to respond Thursday.

CRITICS RESPOND

Sen. John McCain, R-Ariz., and Rep. Mac Thornberry, R-Texas, chairmen of the Senate and House armed services committees, issued a joint statement that said they “intend to carefully and thoroughly review all relevant documentation related to today’s decision.”

“We expect the department to send over its implementation plans as quickly as possible to ensure our Committees have all the information necessary to conduct proper and rigorous oversight,” they said.

One question is whether Congress needs to amend the Selective Service Act, a law that requires all American males to register for the military draft within 30 days of their 18th birthdays. Women are not included in the law.

Carter acknowledged that issue has not yet been resolved, but said it would be in the coming weeks. “To succeed in our mission of national defense, we cannot afford to cut ourselves off from half the country’s talents and skills,” Carter said.