Chinese officials said Monday that the creation of a U.S. Space Force would overly weaponize outer space and endanger peaceful missions.

The Associated Press reported that Geng Shuang, a spokesman for China’s foreign ministry, told reporters that Beijing is “deeply concerned” and “resolutely opposed” to the Trump administration’s establishment of the sixth branch of the U.S. military.

“The relevant U.S. actions are a serious violation of the international consensus on the peaceful use of outer space, undermine global strategic balance and stability, and pose a direct threat to outer space peace and security,” Geng said.

His remarks come just days after President Trump signed the 2020 National Defense Authorization Act, which contained provisions officially authorizing the Space Force first touted by the president in 2018.

The military branch is the first to be designed specifically to counter  threats involving outer space, a possibility that U.S. officials have pointed to for years since China successfully destroyed a satellite with a missile in 2007.

“For the first time since President Harry Truman created the Air Force over 70 years ago — think of that — we will create a brand new American military service. That’s such a momentous statement,” Trump said Friday at a ceremony.

“With my signature today, you will witness the birth of the Space Force, and that will be now officially the sixth branch of the United States Armed Forces. That is something really incredible. It’s a big moment. That’s a big moment, and we’re all here for it. Space, going to be a lot of things happening in space,” he added.