Beijing has disavowed the tribunal ruling and continued to build up and militarily reinforce its positions in the South China Sea. It claims the US and other countries are increasing tensions in the region by sending their warships there in violation of its sovereignty.
Washington counters that its naval presence in the South China Sea supports freedom of navigation under international maritime law.
Underscoring the US stance, the guided-missile destroyer USS Benfold performed a freedom on navigation operation (FONOP) near the Paracel Islands in the northwestern part of the South China Sea on Monday, the US Navy's 7th Fleet said in a statement.
This islands, referred to as the Xisha chain in China, are also claimed by Vietnam and Taiwan, but China has controlled them since the 1970s.
US Navy spokesperson Lt. Mark Langford said Monday's operation challenged the claims by all three parties.
"This freedom of navigation operation ... upheld the rights, freedoms, and lawful uses of the sea recognized in international law by challenging the unlawful restrictions on innocent passage imposed by China, Taiwan, and Vietnam and also by challenging China's claim to strait baselines enclosing the Paracel Islands," Langford said.
China said it put forces in place to "warn and drive away" the US destroyer, which it said violated its sovereignty.
"This is another ironclad evidence of the US' aggressive navigational hegemony and militarization of the South China Sea," PLA Air Force Col. Tian Junli, spokesperson for the PLA's Southern Theater Command, said in a statement after Monday's US FONOP.
"Facts show that the United States is an out-and-out 'South China Sea security risk maker,'" Tian said.
In his statement Sunday, Blinken called on China to "take steps to reassure the international community that it is committed to the rules-based maritime order that respects the rights of all countries, big and small."
"Nowhere is the rules-based maritime order under greater threat than in the South China Sea. The People's Republic of China (PRC) continues to coerce and intimidate Southeast Asian coastal states, threatening freedom of navigation in this critical global throughway," the US secretary of state said, referring to China by its official name.
He called on China to "take steps to reassure the international community that it is committed to the rules-based maritime order that respects the rights of all countries, big and small."
Blinken said the US stands behind the 2016 ruling against China, as reiterated last year by then-Secretary of State Mike Pompeo, who said at the time that "Beijing's claims to offshore resources across most of the South China Sea are completely unlawful, as is its campaign of bullying to control them."
In response to Pompeo's comments, the Chinese Embassy in Washington accused the US of "distorting" international law and "exaggerating" the situation in order to "sow discord."