White House national security adviser Robert O'Brien on Wednesday criticized China over the ouster of opposition leaders in Hong Kong and raised the specter of additional sanctions.

China earlier Wednesday passed a resolution saying any lawmaker supporting Hong Kong's independence or threatening national security should be disqualified, leading to the dismissal of four Hong Kong legislators.

"Beijing's recent actions disqualifying pro-democracy legislators from Hong Kong's Legislative Council leave no doubt that the Chinese Communist Party (CCP) has flagrantly violated its international commitments under the Sino-British Joint Declaration and its promises to the people of Hong Kong, including those under the Basic Law," O'Brien said in a statement.

O'Brien called the mantra of "one country, two systems" a "fig leaf covering for the CCP's expanding one-party dictatorship in Hong Kong," and he pledged the U.S. would use sanctions and other tools to respond.

The Trump administration has long been watchful of the situation in Hong Kong, where Beijing has clamped down on pro-democracy protesters and lawmakers, alarming human rights groups.

But O'Brien's latest statement may carry less weight as President Trump and many of his allies sow doubt about the outcome of last week's presidential election. Networks have projected Joe Biden as the president-elect, but Trump has refused to concede, instead spreading unsubstantiated claims that widespread voter fraud cost him the election.

State election officials have insisted there is no evidence of fraud on a scale that would affect the election, and the Trump campaign has failed to provide concrete evidence of widespread malfeasance.

Secretary of State Mike Pompeo on Tuesday said he looked forward to a "smooth transition to a second Trump administration," then dismissed a question about whether that language undermines calls for democracy elsewhere as "ridiculous."