U.S. Marines and members of all branches of the military are being encouraged to join monthly "Lean In" support groups, where they can visit a "safe place" to talk about gender issues.

The Pentagon is partnering with Sheryl Sandberg, the chief operating officer of Facebook, who began the "Lean In" gender equality movement.

The Marines posted a memorandum on "Lean In Circles" last week, which are intended to make women and men feel more "comfortable" talking about gender in the military.

Defense Secretary Ash Carter announced Thursday that all combat jobs in the military must be open to women, going against the wishes of the Marine Corps. The Marines had asked for its ground combat jobs to remain closed to women after a yearlong study of its integrated units found that women had higher injury rates than men, were less accurate with weapons, and slower than men when completing tactical movements.

Carter’s decision coincides with the Pentagon’s Lean In partnership, which puts an emphasis on gender issues in military life.

"Lean In Circles are small peer groups who meet regularly to learn and grow together," according to the memo. "Lean In Circles will enable both female and male Marines and civilian Marines to come together to share experiences and advice on overcoming challenges in the military and create a safe and confidential place to discuss gender issues."

"Female service members who participate in Lean In Circles report they feel more connected to the women and men in their units and are more comfortable talking openly about gender issues in the military," the memo continued.

Lean In now has a website where service members can sign up for a support group, or start their own.

"[The Department of Defense] DOD believes that participation in such peer mentoring relationships may improve the retention of women and support their career development and professional growth," the memo said.

The Pentagon hopes the Lean In Circles will meet monthly for a "reasonable duration before, during, or after work hours."

"Service members and civilian employees are encouraged to participate in these peer mentoring relationships," the memo said.

Sandberg started Lean In after she gave a TED talk on "the ways women are held back" in 2010, which was the inspiration for her 2013 book Lean In: Women, Work and the Will to Lead.

The movement eventually led to the creation of Lean In Circles.

"Circles are as unique as the individuals who start them, but they all share a common bond: the power of peer support," according to Sandberg’s website. "Women are asking for more and stepping outside their comfort zones, and women and men are talking openly about gender issues for the first time."

Since the Pentagon’s partnership began this fall, 72 military Lean In Circles have been created.

"Combat Boots and High Heels" is an online group with 20 members that is "designed to support women in the military catering to women of all ranks that are attempting to advance themselves professionally and personally."

An Eleanor Roosevelt group has seven members, and the Air Force Reserve Command headquarters online group has one member.

"Lean In Pentagon" has 106 members. None are male.

Sandberg’s movement has started female support groups around the world.

The "Rational Group" in Onchan on the Isle of Man located just outside the United Kingdom, has 10 members from a company that "operates in a very male dominated industry."

"We want to ensure that our women are supported and motivated to be the best they can be and to be confident in their ability whatever the situation or the audience," the circle said.

"Government Gals" in Washington, D.C., provides its 18 members with a "support network" for female federal workers to "discuss their career challenges and opportunities."

There is also "Leaning In Without Falling Over" in Dubai, and "Women Empowering One Another" in Paris, whose mantra is, "Behind every successful woman is herself."

Lean In also has a hash tag, which it uses to promote getting men to clean the dishes and read bedtime stories.

"A man up to his elbows in a sink full of suds. A dad reading to his son at bedtime. A colleague who chimes in when a woman is interrupted," the #LeanInTogether page states. "See the men leaning in for equality and the people celebrating their efforts!"