The national security adviser under former U.S. President Jimmy Carter said Sunday that the United States should open direct talks with Iran over its nuclear program, and dismissed the current negotiations as "absurd." "It's really ironic," Zbigniew Brzezinski told CNN's "Late Edition." "We're not negotiating with Iran, but we are negotiating. Who are we negotiating with? We're negotiating with the negotiators with Iran. And it's an absurd situation." The so-called EU-3 -- Britain, France and Germany -- have been leading negotiations with Iran, which stalled earlier this year. China and Russia have also been involved in negotiations. But national security adviser Stephen Hadley told "Late Edition" that the current framework "is even better" than direct negotiations. However, Brzezinski noted that, in the case of North Korea, the United States is one of six countries involved with direct talks on Pyongyang's nuclear program. "The argument that the administration makes is that we can't negotiate with Iran because it will legitimate them. Well, we're legitimating North Korea, so what's the big deal?" he asked. "The fact is there are serious differences between the United States and Iran, conflicts over security issues, over financial problems, claims and counterclaims. We need to talk to each other to create a measure of security and to be engaged."