The vice president and the second lady, who already have two sons and a daughter, said they`ll be welcoming a third son in late July.

Vice President JD Vance and his wife, Usha Vance, said the newest addition to their family is expected in late July.Mark Schiefelbein / AP file

Second lady Usha Vance is pregnant with her fourth child, she announced Tuesday with Vice President JD Vance.

"We`re very excited to share the news that Usha is pregnant with our fourth child, a boy," the couple said in a social media post.

The pair already share two sons and a daughter. Their joint statement said that Usha Vance and the baby are both doing well, adding that they look "forward to welcoming him in late July."

It is extremely rare for a president or vice president to have a new child while in office.

The White House congratulated the second couple in a social media post.

"The most pro-family administration in history!" the official account said. "CONGRATULATIONS!"

Vance last January called for "more babies in the United States of America," and President Donald Trump in March called himself "the fertilization president." Their comments came ahead of figures showing the overall fertility rate in the U.S. declined for more than 15 years.

The vice president, 41, and his wife, 40, on Tuesday thanked the military physicians who care for their family.

"During this hectic time, we are particularly grateful for military doctors who take excellent care of our family and for the staff members who do so much to ensure that we can serve the country while enjoying a wonderful life with our children," the statement said.

In an interview with NBC News last month, JD Vance said that his marriage with Usha Vance is "as strong as it`s ever been." When discussing his family, the vice president talked about his three kids and how they`re handling being in the spotlight.

"I think that there`s always a limelight on the kids, and that`s both good and bad," he said. "Our 8-year-old really doesn`t like it. He wants to have as private of a life as possible. When we come to an event in the White House and he sees the cameras, he doesn`t love it, and so we try to keep him out of that limelight as much as possible."

"On the flip side, our 5-year-old, who`s a little bit more like me, he probably likes it too much," JD Vance added. "He loves the fact that wherever he goes, people treat him very specially. They always give him candy or cookies."