The US declaration of the South China Sea could be a sign that Washington will strengthen more measures to challenge China's claims, experts say.

On July 13, the State Department posted on the website of Secretary of State Mike Pompeo, rejecting most of China's sovereignty claims in the South China Sea.

Gregory Poling, Center for Strategic and International Studies (CSIS), USA, said that the US has shown more resolute support for the decision of the International Arbitration Tribunal in 2016. He noted that the US does not change.

"The US openly asserts that China violates international law if it catches fish, exploits oil and has other economic activities in the above areas, or hinders these rights of its neighbors", Poling

Lucio Blanco Pitlo, an expert at the Institute for Development Orientation for the Asia-Pacific, Philippines, said that from Pompeo's statement and the US letter sent to the United Nations on June 1 to protest China's claims.

Derek Grossman, an analyst with the Rand Organization, which provides research and analysis to the US armed forces, said that the US move represents a logical progression in rising tensions with China.

"The Secretary of State Pompeo's statement is the latest expression of the overall strategy," Grossman said.

The United States and China from 2019 will increase their strategic competition, when the two sides show their toughness and fierceness in the trade war.

Dr. Collin Koh Swee Lean, an expert at S. Rajaratnam School of International Studies, Singapore (RSIS), said that the US statement will lead to a more comprehensive US strategy in the South China Sea, not merely

According to Collin, the United States has long been criticized for lacking a strategy in the South China Sea, nothing more than carrying out campaigns to patrol and defend freedom of navigation (FONOP) and security cooperation with allies and opponents.

Another measure, in addition to FONOP trips, is that the US could impose sanctions on China, according to Collin.

"If the Trump administration pursues sanctions, it can work," Collin said.

Poling at CSIS argued that Washington now has good grounds to push economic sanctions against China, asserting that China's activities in the South China Sea are illegal.

In Chinese sanctions laws in 2017 and 2019, US lawmakers focused on dredging, construction and other activities on artificial islands that Beijing illegally built.

"There may be more people in China punished than in previous US bills. Enforcement could also be more timely," Poling said.

Based on the statement of US Assistant Secretary of State Stilwell, Bonnie Glaser, also an expert of CSIS, said the subjects that could be punished by the US are Chinese state-owned companies that manage survey ships.

In addition, Glaser said that Washington can encourage environmental protection organizations to sue Beijing for court destruction of marine ecosystems, by dredging activities in rocks.

Considering the impact, Dr. Collin said that in the context of tension in the US and China, related to a range of issues such as Hong Kong, Taiwan, Huawei, Secretary of State Pompeo could raise the level of tension

Grossman shared the view that the US-China tension escalated, saying Chinese Foreign Minister Wang Yi last May accused the United States of pushing relations to "the brink of the Cold War".

In terms of diplomacy, Poling at CSIS predicts that US officials can make tougher statements to China at regional and international forums such as East Asia Summit (EAS), Quartet, group

Poling predicts that US-China tensions will persist in the short term, but in the long term Washington and the international community could lead Beijing toward a compromise that the world can accept.

"It is the best opportunity to peacefully resolve disputes in the South China Sea," Poling said.