WASHINGTON -- US Secretary of State Rex Tillerson on Monday left open the door to dialogue with North Korea, saying it will be up to Pyongyang to decide when they are ready.

Tillerson was speaking at a press conference with his Egyptian counterpart in Cairo, where he was asked whether he sees the start of a diplomatic process with North Korea.

Over the weekend, US Vice President Mike Pence told The Washington Post the US would be willing to talk with North Korea while continuing to put pressure on the regime over its nuclear weapons and ballistic missile programs.

The remark was interpreted as a possible shift in US policy. Washington earlier insisted Pyongyang first commit to its denuclearization as tensions increased over the regime's nuclear and missile testing last year.

"As to the vice president's comments about potentially having talks and whether it's the start of a diplomatic process, I think it's too early to judge," Tillerson said. "As we've said for some time, it's really up to the North Koreans to decide when they're ready to engage with us in a sincere way, a meaningful way."

North Korea knows "what has to be on the table for conversations," he said, apparently referring to a denuclearization commitment.

"We've said for some time that I think it's important that we have -- we're going to need to have some discussions that precede any form of negotiation to determine whether the parties are, in fact, ready to engage in something this meaningful, in order for us to then put together the construct of a negotiation," the top US diplomat said. "So we'll just have to wait and see."

Pence spoke to the Post en route home from the PyeongChang Winter Olympics in South Korea, where he met with South Korean President Moon Jae-in to discuss the North Korea issue.

While Pence was in South Korea, North Korean leader Kim Jong-un invited Moon to visit Pyongyang for a summit.

According to the paper, Moon assured Pence he would tell North Korea there would be no economic or diplomatic concessions in return for talks only. Pence then "felt confident" about endorsing engagement with Pyongyang after the Olympics. (Yonhap)