The White House has stressed that while the U.S. remains open to holding dialogue with North Korea, meaningful steps must come first from Pyongyang toward denuclearization.

U.S. Principal Deputy Press Secretary Josh Earnest told reporters aboard Air Force One en route to Boston on Thursday that the U.S. is “open to credible, authentic negotiations, but it’s going to require clear signals from the North Korean regime” to fulfill its international obligations and keep its commitments to end its nuclear weapons program.

Earnest’s remarks come after North Korea demanded that the UN Security Council sanctions against Pyongyang be withdrawn as a precondition for dialogue with South Korea and the U.S.