The U.S. Army's top officer said more female soldiers may attend the service's elite Ranger School, according to a news report.

Speaking to defense reporters in Washington, D.C., Army Chief of Staff Gen. Raymond Odierno on Thursday said the service will likely extend a pilot program to allow women to continue to attempt the grueling two-month Ranger course, according to a report by Army Times.

"We'll probably run a couple more pilots," Odierno said, according to the report. "It's been a real success for us, and we'll see how it goes from there."

The Airborne and Ranger Training Brigade held its first co-ed Ranger course on April 20 at Fort Benning, Georgia. Nineteen women and 380 men were pre-screened for the combat training course.

Three of the women failed to pass the Ranger Physical Fitness Assessment, a requirement to enter Ranger School. Eight out of 16 female soldiers completed the Ranger Assessment Phase, or RAP week, which consists of day and night land navigation, obstacle courses, skill tests and a 12-mile road march with a rifle, fighting load vest and rucksack weighing approximately 47 pounds.

But the remaining women weren't able to complete the first phase and advance to the second phase of the course. The eight female candidates, along with 101 male candidates, will be recycled to repeat the Darby Phase of Ranger School.

The male and female candidates being recycled through the Darby Phase will not have to repeat RAP week, according to Benning officials. They will begin the phase on May 14 after the next class completes RAP week.

"Ranger School is the Army's toughest course, and this iteration is no exception," Benning officials said in the release.

Ranger School is a punishing ordeal that many young infantry leaders, both officers and sergeants, are encouraged to complete. Only about half of the participants end up graduating.

Senior Army leaders recently decided to allow females to attend the historically male-only, infantry course. The effort is a result of former Defense Secretary Leon Panetta's January 2013 directive that all services open combat-arms roles to women that so far have been reserved for men. The services have until 2016 to make this happen.