Treasury Secretary Steve Mnuchin said Thursday that President Donald Trump's new executive order toughening economic sanctions on North Korea puts foreign banks "on notice that going forward they can choose to do business with the United States or with North Korea, but not both."
"Despite multiple U.N. Security Council resolutions, North Korean dictator Kim Jong Un continues to threaten the world and his neighbors with provocative nuclear and missile tests," Mnuchin told reporters at a press briefing at the United Nations in New York.
"For too long North Korea has evaded sanctions and used the international financial system to facilitate funding for its weapons and mass destruction and ballistic missile programs.
"No bank in any country should be used to facilitate Kim Jong Un's destructive behavior," Mnuchin said.
"Foreign financial institutions are now on notice that going forward they can choose to do business with the United States or with North Korea, but not both."
Trump signed the order earlier Thursday, opening the door wider to blacklisting people and entities doing business with North Korea, including its shipping and trade networks, and further tightening the screws on Pyongyang's nuclear and missile program.
But the president stopped short of going after North Korea's largest trading partner, China, and praised its central bank for ordering Chinese banks to stop doing business with North Korea.
The additional sanctions on Pyongyang showed Trump was allowing for more time for economic pressures to weigh on North Korea after his warning Tuesday of possible military action earlier in his first speech to the United Nations.
Mnuchin referenced Trump's speech in his comments, telling reporters "it is time for all nations to work together to isolate the Kim regime until it ceases its hostile behavior.
"We will continue to work with our allies and partners to stop North Korea from using the financial system to further Kim's reckless behavior," he said.
The sanctions would allow the United States, for instance, to freeze assets of anyone conducting "significant" trade in goods, services or technology with Pyongyang — as well as those of companies backing the country's textile, fishing, and manufacturing industries.
He said the Treasury Department would work with other federal agencies, including the Coast Guard, to enforce the new sanctions.
Mnuchin praised previous U.N. restrictions, saying the new ones went further and allowed the United States to "block any financial institution that doesn't follow through on the U.N. sanctions or additional sanctions."
He said he informed China and other U.S. allies of the president's new order, but declined to disclose the content of those conversations.
The Treasury secretary also declined to comment on a reported move by China's central bank ordering its financial institution to strictly implement U.N. sanctions against North Korea.
"This action is directed at everyone," Mnuchin said. "It is in no way specifically directed at China.
"We look forward to working very closely with them."
He said President Trump has talked with Chinese President Xi Jinping and "we appreciate the way they're working with us."
Mnuchin added "we will call on Russia to do more," declining to be more specific.
In response to a question on how Pyongyang might hit back after the new sanctions, Mnuchin said, "I'm not going to comment on what I expect North Korea to do.
"Obviously, as what we've said the objective is for them to stop their missile tests and give up their nuclear weapons.
"We call on all countries around the world to join us by cutting off all trade and financial ties with North Korea in order to achieve a denuclearized Korean peninsula."
Reuters contributed to this report.