William Burns said the two countries should get ready to resolve issues that will come up after the START I treaty expires in 2009.
START II that followed START I, although it was ratified, has never been activated. In June 2002 Russia withdrew from START II shortly after the United States withdrew from the ABM Treaty. According to the START II treaty signed in 1993, the sides were to have reduced their strategic arms arsenals by two thirds against the January 1993 levels by 2003.
Russia and the U.S. signed the Strategic Offensive Reductions Treaty (SORT) in May 2002, envisioning a reduction in the nuclear arsenals of each side to 1,700-2,200 by the end of 2012.
William Burns said he does not think Russia and America are in a state of "cold war" though they are rivals.
He said the two countries are not enemies and that no one wants a new cold war or a new arms race.
Burns voiced concern over Iran and North Korea's nuclear programs.