President Obama says he expected to sign a new nuclear weapons treaty with Russia next month. US and Russian negotiators are working on a new treaty to replace the 1991 Strategic Arms Reduction Treaty known as START. The current pact signed in the final years of the cold war expires in December. The new treaty would make ever deeper cuts in US and Russian nuclear arsenals and missiles needed to launch those weapons. The United States and Russia also must work out a way to verify that both sides are living up to the agreement.