Driving U.S. warships near China's artificial archipelago is ese-claimed artificial man-made islands are a routine operation and shouldn't be seen as provocative, the U.S. Navy's top officer said told reporters Thursday.

Taking questions from Japanese and international press during the Japan leg of his world tour, Chief of Naval Operations Adm. John Richardson said the Navy sees freedom of navigation operations as part of upholding international law.

"The United States … is a global power and it has a global Navy," Richardson said. "And it should not be a surprise to anybody that we will exercise freedom of navigation through wherever international law will allow.

"We do this routinely around the world. We are present in the South China Sea routinely. And so we see this as part of exercising international rights in international waters."

China has been conducting a massive island construction project in the vicinity of the Spratly Islands, which are a collection of reefs, rocks and other natural features, as a way of furthering its territorial claims to control of virtually all of the South China Sea.

When a reporter asked Richardson to respond to an opinion piece in Chinese media that said the Pentagon was repeatedly provoking China and planning to "charge into" and Chinese "area of core interest," Richardson repeated that freedom of navigation operations are not aggressive, but the practice of conforming to international norms. FONOPS should not be seen as aggressive.

"I think that we have to continue to proceed in accordance with international norms," he said. "[This is] part of routine navigation in international waters, consistent with international rules there: I don't see how these could be interpreted as provocative in any way."

If a freedom of navigation patrol happens soon, it would most likely be conducted by the destroyer Lassen. The Yokosuka, Japan-basedA Navy official confirmed Lassen is steaming in the South China Sea, a Navy official said.

The patrol was still pending approval from the administration, according to a Pentagon official who spoke on background to discuss future operations. said that

In September, David Shear, assistant secretary of defense for Asia-Pacific security, told the Senate Armed Services Committee that The U.S. Navy hasdn't steamed or flown within 12 nautical miles of the islands since 2012, which is before China's island construction project began in earnest, the assistant Defense secretary for Asia-Pacific security told lawmakers in September. Six nations with South China Sea coasts have competing claims to the territory being staked out by China's island building.

Observers say that the U.S. government failure to exercise freedom of navigation transits by the Spratly Islands lends legitimacy to China's claims. Critics of the Obama administration's aversion to carrying out the operation claim that by not conducting freedom of navigation ops in the Spratly Islands, it lends legitimacy to China's claims.

"If you act like they have a legal 12-mile limit, even though the U.S. has said it doesn't recognize it, you are tacitly acknowledging those claims as legitimate," said Bryan Clark, a retired Navy commander and expert with the Center for Strategic and Budgetary Assessments. Clark added that said, adding that even if the claims were legitimate, the U.S. would have the right to pass through under the right of innocent passage.

Experts have also claimed that if the U.S. avoids establishing freedom of navigation in the area that it risks handing the legal precedent to China.

"We need to remind ourselves that U.S. Navy … has been conducting freedom of navigation operations since Jimmy Carter was in office," said Craig Allen, a professor of marine and environmental affairs at the University of Washington School of Law. "If you simply acquiesce to somebody else's claims, you could lose your rights, if you don't exercise them."