He might withdraw from the recently signed U. S.-Russia nuclear disarmament treaty if U. S. missile plans in Europe create "imbalance," Russia's president has said.

American missile defense plans in Europe could conflict with language in the START treaty stating there is an "interconnection between the strategic offensive arms and missile defense," Dmitry Medvedev said, speaking on ABC's "Good Morning America" on Monday.

Medvedev further 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 also said that should Russia consider the European missile defense program, long a sticking point in negotiations, a threat, he would have to consider a "premature end" to the agreement.

The treaty, which was signed on Thursday, would reduce American and Russian nuclear arsenals by a third over seven years. (With Inputs from Agencies)