U.S. Vice President Mike Pence on Friday hailed what he called a step toward denuclearization of the Korean peninsula, but said it was just one step and that the United States would keep up its "pressure campaign" on North Korea.

"Any talks, promises, and assurances from North Korea will be met with reservation, vigilance, and verification," Pence said in a statement. "Planning for the United States and North Korea Summit continues, but as we've said before -– the pressure campaign will continue unabated."