SINGAPORE (AP) — A joint declaration signed by President Donald Trump and North Korean leader Kim Jong Un says the U.S. has committed to providing “security guarantees” to the North.

The document signed at the end of the pair’s historic summit in Singapore on Tuesday also says Kim “reaffirmed his firm and unwavering commitment to complete denuclearization of the Korean Peninsula.”

It’s unclear exactly what Trump has promised Kim in terms of security. Secretary of State Mike Pompeo declined to say Monday whether guarantees might include withdrawing U.S. troops from the Korean Peninsula.

A copy of the text snapped by a photographer at the signing summit says Trump and Kim also discussed how to build “a lasting and robust peace regime on the Korean Peninsula” in their talks.