NASA Administrator Jim Bridenstine took part in a joint presentation by the chiefs of a number of international space agencies at the annual International Astronautical Conference on Monday. At the end of the event, a question was put to the entire group — when do we get to Mars?

After a joke answer of “Tuesday” by ESA Director General Jan Wörner, Bridenstine followed with a serious answer that he believes — provided everyone can get their governments to actually back them and provide the support needed — it’s possible that astronauts could land on Mars by as early as 2035.

“If we accelerate the Moon landing, we’re accelerating the Mars landing — that’s what we’re doing,” Bridenstine said, referring to the agency’s aggressive, accelerated timeline of aiming to land the first American woman and next American man on the Moon by 2024 with the Artemis program.

“If our budgets were sufficient,” Bridenstine said, turning to his colleagues from NASA’s international equivalents, “I would suggest that we could do it by 2035.”

“The goal is to land on the Moon within five years and be sustainable by 2028,” Bridenstine said during a press conference following the agency leadership panel, clarifying that sustainability means “people living and working on another world for long periods of time.”

The caveat Bridenstine offered, that budgets match ambition, is not an insignificant one. NASA just faced a congressional subcommittee budgetary hearing about its plan to get to the Moon by 2024, and faced some heavy skepticism. From NASA’s scientific and technical assessment of Mars mission feasibility for a 2035 target, however, the agency previously discussed this date as early as 2015.