WASHINGTON (Reuters) - The Trump administration plans to announce on Friday what is being billed as the largest package of sanctions yet against North Korea to increase pressure on Pyongyang for its nuclear and ballistic missile tests, a senior administration official said.

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President Donald Trump is expected to talk about the new sanctions during a mid-morning speech to the Conservative Political Action Conference, and the Treasury Department will get into the details later in the day.

A senior administration official, who spoke to Reuters on condition of anonymity, called the new penalties “the largest package of new sanctions against the North Korea regime,” without giving details.

Vice President Mike Pence had given a glimpse of the plan two weeks ago when he spoke in Tokyo on his way to South Korea for the opening of the Winter Olympics, saying stepped-up sanctions would be announced soon.

On Thursday, Pence used tough rhetoric to describe North Korea in remarks to the CPAC gathering in a Washington suburb. He called Kim Jo Yong, the younger sister of North Korean leader Kim Jong Un, is “a central pillar of the most tyrannical and oppressive regime on the planet.”

Kim Jo Yong attended the opening of the Olympics in Pyeongchang and got a red-carpet welcome from South Korean President Moon Jae-in but was shunned by Pence. Trump’s daughter, Ivanka Trump, a senior White House adviser, is due to attend the closing of the Olympics this weekend.

“We stand up to murderous dictatorships. And we will keep standing strong until North Korea stops threatening our country, our allies or until they abandon their nuclear and ballistic missiles once and for all,” Pence said.

North Korea has thus far resisted the “maximum pressure” campaign led by the United States to try to force Pyongyang to cede its nuclear weapons.

U.S. ambassador to the United Nations Nikki Haley said in a speech on Thursday at the University of Chicago that sanctions are having an impact because North Korea now has less money to spend on its ballistic missile tests.

“It is this fact, more than anything else, that prompted the Kim regime to reach out to South Korea and do public relations damage control at the Olympics,” she said.

“Their sources of revenue are drying up. Sending cheerleaders to Pyeongchang was a sign of desperation, not national pride,” she said.