President Donald Trump said sanctions and other pressures are beginning to have an impact on North Korea.
Trump's comments came in Tuesday morning tweet.
Trump appeared to be referring to reports of two recent defections to South Korea. CNN reported a North Korean soldier defected to South Korea late last month. Another North Korean soldier was shot while escaping to South Korea in November, according to the news network.
The BBC reported that South Korea has offered talks with North Korea to find ways to cooperate on next month's Winter Olympics.
The Olympics are scheduled for South Korea. North Korea's leader Kim Jong Un had said he was willing to send a delegation to the Olympics and called for both sides to meet.