WASHINGTON — Defense Secretary Chuck Hagel ordered a high-level review of the state of American nuclear forces on Thursday, days after missile launch officers were caught in a drug investigation and dozens were accused of cheating on their certification exams.

Hagel will convene a meeting in the next two weeks of officials responsible for U.S. nuclear weapons to examine the leadership and culture of the force, said Rear Admiral John Kirby, a Pentagon spokesman.

“To the degree there are systemic problems in the training and professional standards of the nuclear career field, the secretary wants them solved,” Kirby said. “And to the degree leaders have failed in their duties, he wants them held to account.”

The review comes as the Air Force is investigating 10 officers for alleged illegal drug possession at six bases in the United States and Britain, some of them launch officers who are part of the intercontinental ballistic missile (ICBM) force.

While acknowledging wrongdoing by some ICBM officers, Kirby said Hagel was confident U.S. nuclear arms were secure.

The probe became public as Hagel was visiting F.E. Warren Air Force Base in Cheyenne, Wyoming, home of about a third of the United States’ 420 nuclear-armed ICBMs. While there, officials revealed that two launch officers at Malmstrom Air Force Base in Montana had been implicated in the probe.

During the course of the drug probe, investigators also discovered that dozens of officers had been cheating on a key proficiency exam, prompting the suspension of security clearances for 34 and the re-examination of the entire force.

The drug and cheating incidents come just months after the head of U.S. nuclear forces was fired for drunkenness and other inappropriate behavior while on an official nuclear security visit to Moscow. There also have been concerns raised about morale problems in the force.

Kirby told a Pentagon briefing that Hagel’s concern about the health and morale of the workforce had been part of the reason for his visit to F.E. Warren.

“While there he was certainly encouraged by the talent and the professionalism of those airmen with whom he interacted, but he also was reminded of the fact … that not all of them live up to the same high standards required by the gravity of that work,” Kirby said.

The review and action plan by leaders of U.S. nuclear forces is to be completed within 60 days, Kirby said. Hagel also ordered an independent review by former leaders.

“Secretary Hagel believes it is time for the Department of Defense as a whole to place renewed emphasis on examining the health of the nuclear force, in particular those issues that affect the morale, professionalism, performance and leadership of the people who make up that force,” Kirby said.