WASHINGTON (CBS) President Donald Trump is responding to North Korean dictator Kim Jong Un's warning that he now has a nuclear button his desk. The president tweeted, "I too have a nuclear button, but it is a much bigger and more powerful one than his, and my button works."
U.S. Homeland Security Secretary Kirstjen Nielsen was asked about the tweet.
"The president speaks for himself. I think we have to continue, as he said, to take the threat from North Korea very seriously," Nielsen said.
While President Trump is sending messages via Twitter, North and South Korea have a new way to communicate. A North Korean spokesman announced on state TV that a hotline in Korea's demilitarized zone was restored for the first time in nearly two years.
North Korean leader Kim Jong Un says he's open to talks about allowing North Korean athletes to compete at the upcoming Winter Olympics being held in South Korea. South Korean President Moon Jae-In says he is open to meeting with the North without any preconditions. The White House is opposed to talks unless North Korea first abandons its nuclear program.
"Kim Jong Un may be trying to drive a wedge of some sort between the two nations, our nation and the Republic of Korea. I can assure you, that that will not happen," said Heather Nauert, a spokesperson for the State Department.
The U.S. says it will not oppose the talks but doubts Kim Jong Un's sincerity. And Pentagon officials say there is evidence North Korea is preparing for another test of its intercontinental ballistic missiles.
Nikki Haley, the U.S. ambassador to the United Nations, says the U.S. could seek even more economic sanctions against North Korea if they go through with another missile test in violation of UN resolutions.