South Korea is sending the wrong message and undercutting President Trump by encouraging the North Korean regime to attend the Olympics, Sen. Lindsey Graham said Wednesday.

The Olympic talks may lead North Korean leader Kim Jong Un to believe his pursuit of nuclear weapons capable of striking the U.S. is not so unacceptable, and could ratchet up military tensions, Graham, R-S.C., said during a discussion at the American Enterprise Institute.

The two Koreas announced plans Wednesday to form a unified Olympic team and march together at the opening of the Winter Olympics in Pyeongchang, South Korea, next month after a recent thaw in diplomatic relations, according to an AP report.

“South Korea is a great ally, they are in a bad spot. But I think the signals that they are sending to North Korea are undercutting what Trump is trying to do, which will make it more likely that we will build up military capability not less,” said Graham, who is a member of the Senate Armed Services Committee.

The Olympic agreement comes amid warnings from the Trump administration that it will use military force to stop the North from acquiring nuclear weapons capable of striking the U.S.

The U.S. has also spearheaded new United Nations sanctions on Kim’s regime for a string of missile and nuclear tests last year.

“I think what Kim Jong Un is going to see out of this is, ‘How bad could I be?’ I’m going to the biggest party in the world, how bad could I be?” Graham said. “Here’s a simple rule: If you have the largest system of concentration camps in the world, if you systematically rape and torture your own people, and you threaten the world with nuclear attack, you probably shouldn’t go to the Olympics.”