Secretary of State Rex Tillerson Rex Wayne TillersonGary Cohn: 'I haven't made up my mind' on vote for president in November Kushner says 'Alice in Wonderland' describes Trump presidency: Woodward book Conspicuous by their absence from the Republican Convention MORE said that the U.S. is now using "large sticks" instead of carrots to bring North Korea to the table for multilateral negotiations.

"We're not using a carrot to convince them to talk. We're using large sticks. And that is what they need to understand," Tillerson told CBS News's Margaret Brennan in a segment for Sunday's "60 Minutes" program.

Tillerson added that the pressure campaign by the U.S. and its allies against North Korea, including steep economic sanctions, is "having its bite on North Korea."

The top diplomat has maintained that the Trump administration takes a tough stance toward North Korea, although Tillerson late last year raised doubts that the administration would condition future talks on North Korea halting its nuclear program.

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Tillerson said earlier this month that the recent communication between North and South Korea, the first in over 10 years, is a sign that U.S. pressure on North Korea is working. And the top diplomat says the U.S. will be ready for discussions with North Korea in the future.

"My job as chief diplomat is to ensure that the North Koreans know we keep our channels open," Tillerson said. "I'm listening. I'm not sending a lot of messages back because there's nothing to say to them at this point. So I'm listening for you to tell me you're ready to talk."

North Korea will likely be "very explicit" on how they want to initiate dialogue with the U.S., he added.