Washington objects to Beijing's unilateral military steps in the South China Sea and the pace of US freedom of operations trips to the disputed water areas has increased, US National Security Adviser John Bolton told reporters in Singapore on the sidelines of the ASEAN.
According to the joint press release after the talks, both sides agreed to remain committed to "non-confrontation," and support the peaceful resolution of any disputes in the contested region.
China has repeatedly encountered US warships in the South China Sea, with one of the incidents taking place in October; a Chinese Luyang-class destroyer came within 45 yards of the USS Decatur, forcing the ship to manoeuvre to avoid a collision.
The disputes escalated in May when US Secretary of Defense James Mattis noted that despite Chinese President Xi Jinping's promise not to militarize the Spratly Islands, Beijing had moved weapons there. In turn, Beijing stressed that it had the sovereign right to send troops to any part of its territory.
China claims to control the vast majority of the islands, reefs and shoals in the South China Sea, which are also claimed by the Philippines, Vietnam, Malaysia and Taiwan.