The United States plans to blacklist additional entities in China and elsewhere "fairly soon" for their ties with North Korea's weapons programs, a senior State Department official said Tuesday.

Asked if the next round of designations that include Chinese entities and financial institutions could come within 30 days, Susan Thornton, acting assistant secretary of state for East Asian and Pacific affairs, said at a Senate hearing, "I would hesitate to predict exact timetables, but I think you'll see something fairly soon, yes."

"We have been working on coming up with a new list of entities that we think are violating," Thornton said in response to a question by Sen. Cory Gardner, chairman of the Subcommittee on East Asia, the Pacific, and International Cybersecurity Policy.

Thornton made the remarks as President Donald Trump's administration vowed to sanction more individuals and entities enabling North Korea's pursuit of nuclear and missile programs, "including those in China."

The administration pledged to "choke off revenue streams" to North Korea as a way of compelling it to change its provocative behavior, most recently with the July 4 test-launch of its first intercontinental ballistic missile.

In a written statement to the subcommittee, Thornton pressed China, the main economic and diplomatic benefactor of North Korea, to "exert its unique leverage" over its defiant neighbor.

"We recognize that Beijing can and should do more to monitor financial activity within its own borders," she said.

China accounts for about 90 percent of North Korea's official trade and is a major supplier of oil for the country.

In late June, the U.S. Treasury Department sanctioned the Bank of Dandong, a Chinese bank accused of laundering money for North Korea, cutting it off from the U.S. financial system.

The Treasury also blacklisted a Chinese company and two Chinese individuals for their ties to North Korea's development of nuclear weapons and ballistic missiles.

"Together, these actions all send a clear message to the international community -- if you attempt to evade sanctions and conduct business with designated North Korean entities, you will pay a price," Thornton said.

She also demanded that Pyongyang abandon its nuclear ambitions, saying, "We will never recognize North Korea as a nuclear state."