.WASHINGTON — A U.S. naval destroyer was approaching waters near the Spratly Islands in the South China Sea late Monday, the Pentagon said, directly challenging China's claims that the artificial island chain is within its territorial borders.
The U.S.S. Lassen, a guided missile destroyer, was preparing to sail within 12 nautical miles of the islands, making a long-anticipated entry into the disputed waters, officials said. U.S. officials did not inform their Chinese counterparts as they planned the provocative maneuver, saying that to do so would have undercut their message.
"You don't need to consult with any nation when you are exercising the right of freedom of navigation in international waters," John Kirby, the State Department spokesman, said at a news conference.
Kirby said that such a challenge to what he called a questionable sovereignty claim was "one of the reasons you have a navy — to be able to exert influence and defend freedom of navigation on international waters."
China has been reclaiming land in the South China and East China Seas for several years, and the projects in the vicinity of the Spratlys have come under increasing criticism from the United States and its regional allies, including the Philippines. The United States and several Asian nations dispute the legitimacy of the islands built by China.
The Obama administration did not make an immediate announcement of the naval maneuver, and Pentagon officials would only confirm that it was planned, as they had forecast weeks ago.
The White House declined to share any details about the operation, referring questions to the Defense Department. But Josh Earnest, the press secretary, noted that President Barack Obama had stood next to President Xi Jinping of China at a Rose Garden news conference last month and said that the United States would operate, fly or sail anywhere that international law allowed.
"That certainly includes the ability of our Navy to operate in international waters," Earnest said. "This is a critically important principle, particularly in the South China Sea, because there are billions of dollars of commerce that flow through that region of the world every year — maybe even more than that — and ensuring the free flow of this commerce, and that freedom of navigation of those vessels is protected, is critically important to the global economy."
U.S. officials had said for the last month that the Navy would send a surface ship inside the waters claimed by China, a vow widely viewed as a signal to the Chinese that most of the rest of the world does not recognize its claim on the island chain. Obama approved the move this month, administration officials said.
The president signaled the Navy maneuver last month at the annual meeting of the U.N. General Assembly, when he said that the United States had an "interest in upholding the basic principles of freedom of navigation and the free flow of commerce and in resolving disputes through international law, not the law of force."
Defense Secretary Ashton B. Carter has said repeatedly that the U.S. military will operate where international law allows.
China, in what some Asia analysts interpreted as a gesture to pre-empt the U.S. naval maneuver, sent warships into U.S. territorial waters in August. Five Chinese ships came within 12 miles of the coast of Alaska while Obama was visiting the state.
But U.S. military officials said that the two maneuvers were not comparable, citing international maritime laws that allow passage such as the Chinese transit near Alaska if there was no other passageway for a ship to reach its destination.
In the case of the Spratly Islands, one U.S. military official said, there were several other routes that the U.S. destroyer could have used, but the military deliberately chose to enter the waters that China claims as its territory.
In recent years, China has been claiming large parts of the strategic waterway by enlarging rocks and submerged reefs into islands big enough for military airstrips, radar equipment and lodging for soldiers, U.S. officials said.
Although China claims much of the South China Sea as sovereign territory, the 12-mile zone around the new islands is particularly delicate because international law says that artificial islands do not have sovereign rights up to the 12-mile limit.
The United States has not traveled close to the Chinese-occupied islands in the South China Sea since at least 2012. In May, a U.S. Navy surveillance plane flew near three of China's five artificial islands but did not go within the 12-mile zones. Chinese Navy radio operators warned the Americans to leave the area.