BEIJING » The top U.S. admiral said Wednesday that friendly exchanges with China’s navy are conditional on safe interactions at sea, an indication of Washington’s concern over recent fractious encounters with Chinese forces in and over the disputed South China Sea.

On a visit to the northern Chinese port of Qingdao, Chief of Naval Operations Adm. John Richardson said he backs more exchanges, but added, “In this area we must judge each other by our deeds and actions, not just by our words.”

“I am supportive of a continued and deepening navy-to-navy relationship, but I will be continuously reassessing my support conditioned on continued safe and professional interactions at sea,” Richardson said, according to a Navy news release.

Richardson is on what the Navy is calling a five-day visit to “improve mutual understanding and encourage professional interaction between the two navies.” In Qingdao, he visited the headquarters of China’s North Sea Fleet and met with its commander, Vice Adm. Yuan Yubai.

Richardson “underscored the importance of lawful and safe operations in the South China Sea and elsewhere where professional navies operate,” the Navy said.

He said the U.S. Navy would continue to conduct “routine and lawful operations” around the world, including in the South China Sea, in order to protect “the rights, freedoms and lawful uses of sea and airspace guaranteed to all.”

“This will not change,” Richardson said.

He was also scheduled to visit China’s first aircraft carrier, the Liaoning, along with a submarine training base.

On Monday, he met in Beijing with his Chinese counterpart, Wu Shengli, who took a hard line on China’s claim to virtually the entire South China Sea, where China has been building airstrips, harbors and military facilities on man-made islands created by piling sand on top of coral reefs.

The U.S. refuses to recognize the new features as possessing the legal status of islands and has emphasized the point by sending Navy ships to sail close to them on so-called freedom of navigation missions. That has incensed China, which has responded by dispatching its own vessels to threaten and harass the U.S. ships.

Chinese planes have also engaged recently in what the U.S. described as unsafe maneuvering close to American surveillance aircraft.

Coinciding with Richardson’s visit, China is also holding military drills in an area of the South China Sea south of its island province of Hainan. A former information minister, Zhao Qizheng, said at a news conference in Singapore on Tuesday that the drills were a direct response to frequent U.S. exercises in the area.

Meanwhile, China’s highest-ranking officer, Gen. Fan Changlong, is making an inspection visit to the Southern Theater Command, which includes the South China Sea.

On Tuesday, Fan ordered officers and others to “profoundly understand the complexity of the grim situation facing our nation’s security, step up all preparations for military struggle, ensure that orders are followed, and that we can get there and fight to win.”

Despite suspicions on both sides, U.S.-China military-to-military exchanges have steadily gained pace in recent years. China’s navy is currently taking part for the second time in the Rim of the Pacific, or RIMPAC, the world’s largest naval drills, hosted by the U.S. off Hawaii and including military forces from 26 nations.

U.S. law limits the scope of U.S. military drills with China to areas such as search and rescue and humanitarian and disaster relief.

It’s unclear what specific issues Richardson has discussed, but Wu told him that China had no intention of abandoning its plans to fully equip its newly created islands and would resolutely defend its interests and sovereignty claims in the region. China has firmly rejected last week’s ruling by an international arbitration panel in The Hague that essentially voided China’s South China Sea maritime claims.