China and the U.S. did not budge Saturday over Beijing’s assertive development in the disputed territories of the South China Sea, with Foreign Minister Wang Ji politely but pointedly dismissing Washington’s push for a diplomatic solution to ease the tensions.

Wang and Secretary of State John Kerry stressed the importance of dialogue to resolve the highly-contested claims in the waterway. But neither diplomat showed any sign of giving ground over Chinese land reclamation projects that have alarmed the U.S. and several other countries in Asia.

The U.S. and most members of the Association of Southeast Asian Nations want to halt China’s projects, which they suspect are aimed at building islands and other land features over which China can claim sovereignty.

"We are concerned about the pace and scope of China's land reclamation in the South China Sea," Kerry said. He urged China to speed up talks with ASEAN on guidelines for handling maritime activity in disputed areas.

The goal is to help "reduce tensions and increase the prospect of diplomatic solutions," Kerry said.

"I think we agree that the region needs smart diplomacy in order to conclude the ASEAN-China code of conduct and not outposts and military strips," Kerry told reporters at a news conference with Wang.

Wang indicated the China was prepared to talk, but it would not back down on the construction that, he said, “is something that falls fully within the scope of China’s sovereignty.

"The determination of the Chinese side to safeguard our own sovereignty and territorial integrity is as firm as a rock, and it is unshakable," he said.

"It has always been our view that we need to find appropriate solutions to the issues we have through communications and negotiations that we have among the parties directly concerned with peaceful and diplomatic means on the basis of respecting historical facts and international norms. This position will remain unchanged in the future."

Wang also noted that the differences between China and the U.S. could be managed “as long as we can avoid misunderstanding and, even more importantly, avoid miscalculation.”

The Chinese claims and land reclamation projects have rattled the region where South China Sea islands and reefs are contested by China and five other Asian governments. Activities have led to clashes, accompanied by nationalistic protests and occasional serious diplomatic implications.

The U.S. says it has no position on China’s sovereignty claims but insists they must be negotiated. Washington also says ensuring maritime safety and access to some of the world’s busiest commercial shipping routes is a U.S. national security priority.

China has bristled at what it sees as U.S. interference in the region and wants to negotiate with the ASEAN countries individually, something those much smaller nations fear will not be fair.

In one disputed area, the Spratly Islands, U.S. officials say China has reclaimed about 2,000 acres of dry land since 2014 that could be used as airstrips or for military purposes. The U.S. argues that man-made constructions cannot be used to claim sovereignty.

Obama administration officials have declined to comment on reports that it may deploy military assets, or that it is considering a demonstration of freedom of navigation within 12 nautical miles of the islands' notional territorial zone. But they have said many of the features claimed by China in the disputed Spratlys are submerged and do not carry territorial rights, and said that China cannot "manufacture sovereignty."

Despite the clear disagreements over the South China Sea, Kerry and Wang said they were on track to make progress in other areas, notably on climate change, the fight against violent extremism, and preparations for the next round of the U.S.-China Strategic and Economic Dialogue in June and Chinese President Xi Jinping's visit to Washington in September.

They expressed pleasure with their cooperation in the Iran nuclear talks, their solidarity in trying to denuclearize North Korea and combat diseases such as the deadly Ebola virus.

The Associated Press contributed to this report