The two sides are trying to hammer out a deal before the March 1 deadline when US tariffs on $200 billion worth of Chinese imports are scheduled to increase to 25 percent from 10 percent.
China is pitted against smaller neighbors in multiple disputes in the South China Sea over islands, coral reefs and lagoons in waters crucial for global commerce and rich in fish and potential oil and gas reserves.
Two US warships sailed near islands claimed by China in the South China Sea on Monday (Feb 11), a US official told Reuters, a move likely to anger Beijing at a time of tense relations between the world's two biggest economies.
During that operation, a Chinese destroyer came within 41kms of the U.S. warship, forcing it to manoeuvre to avoid a collision. When asked if the Navy's move would affect the talks, Chinese Foreign Ministry spokeswoman Hua Chunying called it "a series of USA tricks, "according to Reuters".More news: Winter Weather Advisory posted, wintry mix likely
Cmdr. Clay Doss, U.S. Seventh Fleet public affairs officer, told Fox News in a statement: "Guided-missile destroyers USS Spruance (DDG 111) and USS Preble (DDG 88) conducted freedom of navigation operations (FONOPS) in the South China Sea".
The USS Spruance was one of the warships which conducted the operation, which illustrates the continuing USA military presence in the area, to which China routinely objects.
Monday's operation was carried out "to challenge excessive maritime claims and preserve access to the waterways as governed by global law", Commander Clay Doss, a spokesman for the US Navy's 7th Fleet, said.
The US labelled the Chinese warship's actions unsafe and unprofessional, while Beijing said the US was threatening the safety and sovereignty of China.More news: Fitbit has launched two fitness trackers but you can't buy them
Freedom of navigation operations, or FONOPS, are meant to remind other countries that all nations can operate in worldwide waters. In January, the destroyer USS McCampbell challenged China's claims to the Paracel Islands.
China defends its construction as necessary for self-defense and says it is the United States that is responsible for ratcheting up tensions in the region by sending warships and military planes close to islands Beijing claims.
During that operation, a Chinese destroyer came within 45 yards of the USA warship, forcing it to maneuver to avoid a collision.
Vietnam, the Philippines, Brunei, Malaysia, Indonesia and Taiwan have competing claims in the region.More news: NASA’s faraway space snowman has flat, not round, behind
The two countries are also at loggerheads over regional security, with the USA offering support to the island nation of Taiwan, which China also claims as its own.