Analysts say mutual wariness is keeping cooperative efforts on space exploration between the United States and China in low gear.

Although Presidents Barack Obama and Hu Jintao pledged this week to continue those efforts, neither nation has been overly eager to share its technology with the other, The Washington Post reported Saturday.

"What you have are two major powers, both of whom use space for military, civilian and commercial purposes," said Dean Cheng, an expert on China's space program at the Heritage Foundation, adding there is "a lot of very wary, careful, mutual watching."

The Post said the situation has been complicated by U.S. restrictions on technology exports and the fact that the military controls the more-sensitive aspects of China's program.

China has been pushing an ambitious agenda that includes space stations and manned missions to the moon, while the United States is focused more on unmanned exploration. Still, the Post said, space is seen by the Obama administration as a promising area for cooperation.