"Currently, there’s no plans to create a bilateral arrangement with China on the exchange of samples," Green said at a Tuesday meeting of the Lunar Exploration Analysis Group, as quoted by SpaceNews.
"Over time, focused efforts can be and have been done [to win approval by the White House and Congress for cooperation]," Green said, adding that "we have mechanisms, and we would use those mechanisms as we move into the future."
Last year, China successfully completed its Chang’e 5 lunar sample return mission, becoming the third country in human history after the United States and the Soviet Union to successfully perform such a mission.
A China National Space Administration graphic showing blast-off of the sampling capsule from the Chang'e-5 lunar lander from the moon's Oceanus Procellarum.
China is seeking to construct a prototype of a scientific research station on the Moon by 2030 and is planning to carry out lunar scientific research during the upcoming Chang'e 6, Chang'e 7 and Chang'e 8 missions.