Beijing hit back Tuesday at the US branding of Chinese pursuits in the South China Sea as illegal, saying the accusation was “unjustified’ and a bid to sabotage regional peace.

“We advise the US side to earnestly honor its commitment of not taking sides on the issue of territorial sovereignty, respect regional countries’ efforts for a peaceful and stable South China Sea and stop its attempts to disrupt and sabotage regional peace and stability,” the Chinese embassy in Washington said in a statement.

Also read: US Navy warship again challenges Beijing’s South China Sea claims

Earlier, US Secretary of State Mike Pompeo said in a statement that ”China has offered no coherent legal basis for its ambitions in the South China Sea and for years has been using intimidation against other Southeast Asian coastal states.”

“We are making clear: 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,” said Pompeo, a prominent China hawk within the Trump administration.

Also read| China military exercises in South China Sea will ‘further destabilise’ the situation: Pentagon

The US has long opposed China’s expansive territorial claims on the South China Sea, sending warships regularly through the strategic waterway to demonstrate freedom of navigation there. Monday’s comments reflect a harsher tone.

“The world will not allow Beijing to treat the South China Sea as its maritime empire,” Pompeo said.

The relationship between the United States and China has grown increasingly tense over the past six months over Beijing’s handling of the coronavirus pandemic, its tightened grip on Hong Kong and its crackdown on China’s Uighur Muslim community.

China claims 90% of the potentially energy-rich South China Sea, but Brunei, Malaysia, the Philippines, Taiwan and Vietnam also lay claim to parts of it, through which about $3 trillion of trade passes each year. Beijing has built bases atop atolls in the region but says its intentions are peaceful.

Beijing routinely outlines the scope of its claims with reference to the so-called nine-dashed line that encompasses about nine-tenths of the 3.5-million-square-kilometer South China Sea on Chinese maps.

“This is basically the first time we have called it illegitimate,” said Chris Johnson, an analyst with the Center for Strategic and International Studies. “It’s “fine to put out a statement, but what you going to do about it?”