President Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE said in tweets early Wednesday that there is now a "good chance" that North Korean leader Kim Jong Un will do "what is right for his people and for humanity," but cautioned that sanctions and pressure must be maintained on Pyongyang.

For years and through many administrations, everyone said that peace and the denuclearization of the Korean Peninsula was not even a small possibility. Now there is a good chance that Kim Jong Un will do what is right for his people and for humanity. Look forward to our meeting! — Donald J. Trump (@realDonaldTrump) March 28, 2018

ADVERTISEMENT

Received message last night from XI JINPING of China that his meeting with KIM JONG UN went very well and that KIM looks forward to his meeting with me. In the meantime, and unfortunately, maximum sanctions and pressure must be maintained at all cost! — Donald J. Trump (@realDonaldTrump) March 28, 2018

The White House said late Tuesday that China briefed the administration on Kim's unannounced visit to Beijing, and stressed that the U.S. policy of "maximum pressure" on North Korea is working.

“The United States remains in close contact with our allies South Korea and Japan,” press secretary Sarah Huckabee Sanders said. “We see this development as further evidence that our campaign of maximum pressure is creating the appropriate atmosphere for dialogue with North Korea.”

Kim visited China on Monday for the first time since assuming power in 2011.

Chinese state media confirmed that President Xi Jinping pushed for the meeting, and quoted Kim as saying North Korea could be open to denuclearization on the Korean Peninsula in the future.

"The issue of denuclearization of the Korean Peninsula can be resolved, if South Korea and the United States respond to our efforts with goodwill, create an atmosphere of peace and stability while taking progressive and synchronous measures for the realization of peace," Kim said, according to Chinese state news agency Xinhua.

While tensions have risen between Washington and Pyongyang following numerous North Korean intercontinental ballistic missile tests, Trump said earlier this month that he had agreed to a meeting with Kim.