During a speech at the Pentagon, the US vice president said the service is needed to ensure America's dominance in space amid heightened threats from China and Russia.
He added that while space was once peaceful and uncontested, it is now crowded and adversarial.
In a tweet published ahead of his speech, Mr Pence referred to space as the "next battlefield".
"Trump is committed to preparing for the next battlefield where America’s best and bravest will be called to deter and defeat a new generation of threats to our people and our nation…The time has come to establish the United States," he wrote.
President Trump has repeatedly said that the US must create a space force and tweeted following Mr Pence's announcement: "Space Force all the way!"
Mr Trump directed the US Department of Defence to begin the process of establishing Space Force in June. The new military branch is an effort to stop "potential adversaries" who the White House has said recognises the importance of space to the US.
"The Director of National Intelligence has warned that multiple countries, including Russia and China, are developing both destructive and nondestructive anti-satellite weapons that could come online within a few years," a White House memo read.
In his speech at the Pentagon, Mr Pence referenced Mr Trump's inaugural speech last year in which he committed to unlocking the "mysteries of space" as president. Mr Pence proclaimed that the president "has kept his promise to restore America's proud legacy of leadership in space".
In a post published to Twitter, the US vice president shared details on the Department of Defence report on Space Force, which requires approval from Congress, highlighting four actions: Create US Space Command, Establish elite Space Operations Force, Create Space Development Agency and Stand up and Scale Up the US Space Force (creating a new position, an assistant secretary of defence, who will oversee the growth and expansion of the new branch of service).
US Secretary of Defence Jim Mattis, who once opposed the proposal to create a new branch of military, has recently told reporters he supports the plan's goal to address "space as a developing war-fighting domain". He added: “This is a process we’re in".
Mr Pence also announced that Mr Trump had signed three Space Policy Directives and had revived the National Space Council which the vice president is chair of. The proposed Space Force would join the five branches of the US Armed Forces – Air Force, Army, Coast Guard, Marine Corps and the Navy.
"To be clear, the Space Force will not be built from scratch, because the men and women who run and protect our nation's space programmes today are already the best in the world," Mr Pence said. "Since the dawn of the space age, America has remained the best in space."
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