NEW YORK/HANOI -- The U.S. government doubled down Tuesday on its rejection of Chinese maritime claims in the South China Sea, with a senior official warning that Washington could respond with sanctions against Chinese officials and enterprises for coercive acts.
"By claiming 'indisputable sovereignty' over an area larger than the Mediterranean and trampling the rights of others, Beijing threatens the existing order that has given Asia decades of prosperity," said David Stilwell, assistant secretary of state for the Bureau of East Asian and Pacific Affairs, at a virtual event hosted by the Washington-based Center for Strategic and International Studies.
Noting that this week marks the fourth anniversary of the 2016 arbitral tribunal ruling at the Hague that sided with the Philippines and rejected Beijing's "nine-dash line" maritime claims, Stilwell said that "the world cannot -- and will not -- allow Beijing to treat the South China Sea as its maritime empire."
When asked if sanctions were a possibility, he replied, "Nothing's off the table ... Absolutely, there is room for that."
Governments across Asia watched U.S. Secretary of State Mike Pompeo's Monday announcement closely, mostly welcoming the move.
Japanese Foreign Minister Toshimitsu Motegi told reporters after a cabinet meeting that Pompeo's statement shows "the unshakable commitment of the U.S. to regional peace and stability." Members of the Association of Southeast Asian Nations, which expressed concern about Chinese activities in the South China Sea after a summit late last month without calling out Beijing by name, largely welcomed the statement as well.
"We strongly agree with the position of the international community that there should be a rules-based order in the South China Sea," Philippine Defense Minister Delfin Lorenzana said.
"It is in the best interest of regional stability that China heed the call of the community of nations to follow international law and honor existing international agreements," he said.
In Taiwan, Foreign Ministry spokeswoman Joanne Ou told reporters that the government "opposes any attempt by a claimant state to use intimidation, coercion, or force to resolve disputes."
But skepticism about Washington's commitment to the region remains strong in many quarters.
U.S. President Donald Trump's decision to skip last November's ASEAN summit in Bangkok angered many, who saw the move as a slight of Southeast Asia. China, by contrast, has used its financial clout to expand its influence there, swaying such less-developed countries in the bloc as Cambodia.
Harry Roque, spokesperson for Philippine President Rodrigo Duterte, avoided directly commenting on Pompeo's statement when asked about it in a press briefing Tuesday. The U.S. and China both seek to bring Manila into their camp, but "our position here is to advance our national interest," he said.
Derek Grossman, senior defense analyst at the Rand Corp., said Southeast Asian maritime counterclaimants in the South China Sea will likely take the U.S. policy shift in different ways.
"Vietnam and the Philippines will probably embrace the move as they have bore the brunt of Beijing's excessive and overlapping claims," he said. "However, Malaysia and Brunei may be less keen to the development as they have sought to keep relations with both the U.S. and China on an even keel amid increasing great-power competition."
Grossman said it will be interesting to see how Indonesia reacts. "Although Indonesia is not an official counterclaimant in the South China Sea, it has nevertheless become the target in recent years, and particularly in the last few months, of Chinese pressure at the Natunas Islands," he said. "My bet is that it won't want to rock the boat much either as it benefits significantly from China's Belt and Road Initiative and has been able to manage tensions around the Natunas."
Stimson Center senior fellow Yun Sun said: "ASEAN's default position is not to pick a side. I don't think it is inclined to change that now."
Sun pointed to the region's ever-deepening economic ties with China. "Southeast Asian countries have become China's largest trading partner during the first half of this year," she said. "Given the complementarity of Chinese and Southeast Asian economies and the geographical proximity, it will be very hard for Southeast Asian countries to limit the trade."
"After all, they are not in as good a position as the developed countries in Europe and North America to turn away from the Chinese products," Sun said.
Given a choice, "Southeast Asian states do not want to choose between the U.S. and China," said Taylor Fravel, professor of political science and director of the Security Studies Program at the Massachusetts Institute of Technology. "But they also want to be able to assert their maritime claims and jurisdiction."
"The statement may create an expectation among other claimants that the United States may take actions to defend their claims, but the statement itself creates no such obligation, only an expectation," he said.
In Beijing, Chinese Foreign Ministry spokesperson Zhao Lijian called Pompeo's statement "an irresponsible act."
Arguing that Beijing officially published the nine-dash line marking China's territorial claims in 1948, as opposed to Pompeo's assertion that it was announced in 2009, Zhao said his country "has effectively exercised jurisdiction over relevant islands, reefs and waters in the South China Sea for thousands of years."
This comes amid near-daily reports in Chinese state media on purported threats to the South China Sea and its airspace, such as U.S. military reconnaissance aircraft flying near the Chinese mainland for three straight days through July 8.
A diplomatic source in Beijing speculated that the heavy press coverage aims to "lay the groundwork for establishing an air defense identification zone in the South China Sea" -- an area where it would identify and monitor air traffic and reserve the right to scramble fighter jets to intercept intruders.
Asked in late June about reports that China could set up such a zone in the South China Sea, Zhao said that "every country has the right to establish an ADIZ and to decide whether to establish an ADIZ based on the intensity of the threats it faces in air defense security."
Additional reporting by Wajahat Khan in New York and Koya Jibiki in Jakarta.