United States President Donald Trump on Monday used a term from the history of American racial segregation while directing the Department of Defense and the Pentagon to establish a “space force” as the sixth branch of the country’s armed forces.

“We are going to have the Air Force and we are going to have the Space Force: separate but equal, it is going to be something so important,” he said in the White House during a meeting of his National Space Council.

“We must have American dominance in space,” Trump added, according to CNN. “Very importantly, I’m hereby directing the Department of Defense and Pentagon to immediately begin the process necessary to establish the Space Force as the sixth branch of the armed forces. That’s a big step.”

The term “separate but equal” came to be commonly used after a US Supreme Court verdict in 1896. The Supreme Court, in Plessy vs Ferguson, ruled that racially separate facilities, if equal, did not violate the country’s Constitution. The legal rationale for this was subsequently deemed unconstitutional by a series of US Supreme Court decisions in the mid-20th century.

In his speech on Monday, Trump claimed that national pride was at stake, and that the United States must always stay ahead in space, The Guardian reported. “It’s going to be important monetarily and militarily,” he said. “But so important for right up here – the psyche. We don’t want China and Russia and other countries leading us.”

The US president also asked Joseph Dunford, chairperson of the joint chiefs of staff, to begin the creation of a space arm of the military. Dunford replied, “We got it.”

Trump has faced opposition to the idea of a space force not just from members of the opposition Democratic Party, but also from members of his own government. In October, US Secretary of Defense Jim Mattis had written a memo opposing the programme.

On Monday, Bill Nelson, the Democratic senator for Florida, claimed that military generals had told them they did not want a space force, and that the president could not get it without the approval of the Congress.