Washington (CNN) President Donald Trump will not meet with North Korean leader Kim Jong Un unless North Korea takes "concrete and verifiable actions" toward denuclearization, White House press secretary Sarah Sanders said Friday.

"They have made some major promises. They have made promises to denuclearize. They have made promises to stop nuclear and missile testing," Sanders said. "We're not going to have this meeting take place until we see concrete actions that match the words and the rhetoric of North Korea."

Sanders' comments Friday cast doubt on the President's much-ballyhooed agreement to meet the North Korean leader, with the White House appearing to impose new conditions that were not apparent a day earlier. The South Korean national security adviser said Kim is "committed to denuclearization," but there was no indication that North Korea had promised to take steps toward denuclearization in order to secure a meeting with the US President.

Instead, Kim only promised to stop nuclear and ballistic missile testing and said he accepted the right of the US and South Korea to move forward with joint military exercises later this year.

Sanders' words on Friday also marked the White House's first comments preconditioning the meeting. In a statement the previous evening, Sanders said Trump "will accept the invitation to meet with Kim Jong Un at a place and time to be determined" and that the US looks "forward to the denuclearization of North Korea."

Read More