NASA Administrator Jim Bridenstine and his Chinese counterpart, Zhang Kejian, spoke optimistically about increased space cooperation today while acknowledging that such decisions involve political considerations that are out of their hands. Both are participating in events at the 2018 International Astronautical Congress (IAC) in Bremen, Germany.

Bridenstine tweeted a photo of himself and Zhang saying the two had met to discuss “respective program priorities”

It was my honor to host Administrator Zhang Kejian of the China National Space Administration this morning at #IAC2018. We discussed our respective program priorities. pic.twitter.com/agoAVyNI5p — Jim Bridenstine (@JimBridenstine) October 1, 2018

The two participated in a “Heads of Agencies” panel discussion later in the day. Zhang spoke first, summarizing China’s space program including its plans to land a probe (Chang’e-4) on the lunar far side. When Bridenstine’s turn came, he said China’s lunar far side program is “exciting” because it will provide data and information that can be used for future operations at and around the Moon.

Zhang, Director of the China National Space Administration (CNSA), was similarly optimistic, emphasizing that China’s lunar program is open to international cooperation and collaboration. He referenced a meeting with the head of Russia’s space agency, Dmitry Rogozin, two days ago and with Bridenstine this morning about possible bilateral cooperation. He characterized the responses as “very positive.”

Rogozin is not at the conference. He is not allowed to travel to Europe (or the United States) because of sanctions imposed when he was Deputy Prime Minister of Russia, a time period that included Russia’s annexation of Crimea and subsequent actions in Ukraine. Roscosmos was represented on today’s panel by its Deputy Director for International Affairs Dmitry Loskutov.

Bridenstine responded to Zhang by saying that NASA and CNSA already cooperate on aeronautics and studies of glaciers, for example, but “that’s not to say we align on everything and some decisions are above my pay grade.” Nonetheless, he looks forward to exploring opportunities. Zhang agreed, mentioning exchanges of data on collision avoidance as an example.

Despite the warm words between Zhang and Bridenstine, U.S. law prohibits NASA from engaging in bilateral space cooperation except in specific circumstances. Called the Wolf Amendment after former Congressman Frank Wolf (R-VA), who first put it into NASA’s annual appropriations bill, the provision allows bilateral cooperation only if NASA certifies in advance that it does not pose any risk of technology transfer or involve interactions with officials who violate human rights. Wolf’s successor as chairman of the House appropriations subcommittee that funds NASA, Rep. John Culberson (R-TX), holds the same views as Wolf and includes the provision in NASA’s bill each year.