President Trump signed a directive Monday instructing NASA to return astronauts to the moon, and to eventually send them to Mars.

“This time we will not only plant our flag and leave our footprint, we will establish a foundation for an eventual mission to Mars, and perhaps someday to many worlds beyond,” Trump said during an afternoon signing ceremony at the White House.

“This directive will ensure America’s space program once again leads and inspires all of humanity,” Trump said. ‘This is a giant step toward that inspiring future and toward reclaiming America’s proud destiny in space.”

Before turning the podium over to Vice President Mike Pence, Trump added: "Space has so much to do with so many applications, including a military application. So we are the leader and we’re going to increase it many fold.”

Pence said the document called Space Policy Directive 1 (SPD-1) affirmed the National Space Council’s October recommendation to return astronauts to the moon for the first time since 1972. That council is chaired by Pence and has the NASA administrator and many Cabinet secretaries as members.

Pence said the directive “makes that recommendation official national policy.”

Attendees at the directive signing included former U.S. Sen. Jack Schmitt, R-N.M., the last living human being to set foot on the moon during the Apollo 17 mission in 1972. Schmitt is one of six living astronauts who walked on the moon over six separate missions beginning in 1969.

Astronaut Buzz Aldrin, the second man to walk on the moon, was also present, according to a pool reporter, though he was not recognized by Trump or listed by the White House as a notable attendee.

It’s not immediately clear how the Trump administration plans to fund the push to return to the moon. White House press secretary Sarah Sanders declined to comment on funding during the daily press briefing, which happened before the official policy signing.

Although the signing event struck a patriotic tone, an informational email sent by the White House suggested an inclusive and international path forward, saying: “The United States will work with other nations and private industry to return astronauts to the Moon, developing the technology and means for manned exploration of Mars and other destinations in our solar system.”