BEIJING — By declaring Tuesday that it would soon complete its contentious program of building artificial islands in the South China Sea, Beijing hopes to diminish tensions with the United States while reassuring its home audience that it has delivered on its pledge to resist American military pressure, experts said.

Leaders from the United States and China are set to meet next week in Washington at a major annual conference, the Strategic and Economic Dialogue. A topic of the talks there is expected to be the Obama administration’s opposition to China’s building in the disputed waters, including the construction of a runway capable of handling military aircraft.

After those talks, China’s leader, Xi Jinping, is scheduled to make his first visit to Washington as president in September.

“We need to find some way to let this topic not become so prominent, and China wants to head off the activity,” said Shi Yinhong, a professor of international relations at Renmin University and an adviser to the Chinese government. “We have a lot of other things to do.”