Russian president Dmitry Medvedev said in an exclusive interview with "Good Morning America" that he would consider withdrawing from the nuclear disarmament treaty he and President Obama signed last week, should the U.S. missile defense program in Europe create an "imbalance."
In an interview with ABC News' George Stephanopoulos, Medvedev said the two countries negotiated specific language, or a "formula," in the preamble of the new START treaty that states there is an "interconnection between the strategic offensive arms and missile defense."
"So if those circumstances will change, then we would consider it as the reason to jeopardize the whole agreement. That doesn't mean that because of that rule, if the American side starts to build up the missile system the treaty would automatically lose its power," Medvedev said.
"[If] the other party radically multiplies the number and power of its missile defense system, obviously that missile defense system is indeed becoming a part of the strategic offensive nuclear forces, because it's capable of blocking the action of the other side. So an imbalance occurs, and this would be certainly the reason to have a review of that agreement," Medvedev said.
This issue has long been a sticking point in negotiations between the two countries and Medvedev said should his country feel the missile defense program is a threat, then he would pose the question about a "premature end" to the agreement, but said he hopes that it would not come to that.
Following the signing Thursday of the treaty, which would reduce America's and Russia's nuclear arsenals by a third over seven years, Obama told Stephanopoulos that he is confident the Russians would not withdraw.
"We were firm, and are now absolutely confident that this in no way impedes our ability to move forward on the missile defense program, that's designed not to target Russia," he said in the ABC News interview.
CLICK HERE to read the full transcript of the interview.
Following 16 meetings and phone calls with President Obama, Medvedev said he considers him a "comfortable partner" and says he finds it "interesting" to meet with him.
"The most important thing that distinguishes him from many other people -- I won't name anyone by name -- he's a thinker, he thinks when he speaks," Medvedev said, but would not say who he was speaking about because he didn't want to offend anyone.
The Russian president said he found his American counterpart to be knowledgeable and a good listener, something he said was a good quality in a politician.
"There was no instance in our meetings with Mr. Obama where he wasn't well prepared for the questions. This is very good. And after all, he's simply a very pleasant man with whom it's a pleasure to deal," Medvedev said.
Ever since Medvedev, the handpicked successor of previous President Vladimir Putin, was elected in March 2008, questions have been raised about whether he or Putin, currently the Russian prime minister, is really in charge of the country.
Medvedev told Stephanopoulos that he found that question "annoying" and is "tired" of answering it.
"The decision is taken by the person who is designated to do it by law. If you consider the questions of foreign and domestic politics, the defense, the security, this is only the president. And nobody else," Medvedev said.