The United States and Russia have reached an agreement to slash their strategic nuclear arsenals by two thirds over 10 years. A signing ceremony will take place on May 24 during President Bush's trip to Russia.
Both sides indicated last year that they want to cut their nuclear arsenals.
President Bush called it the start of an era of enhanced mutual security. "This treaty will liquidate the legacy of the Cold War," he said. "When I sign the treaty with President Putin in Russia, we will begin the new era."
He spoke shortly after U.S. and Russian arms negotiators completed their work in Moscow. In the Russian capital, President Vladimir Putin made an almost simultaneous announcement.
Mr. Putin said he was pleased with the results of the negotiations.
White House officials say they represent a "win" for both countries. They say the Russians got the formal treaty they wanted, while the United States retained some flexibility in the ways it takes warheads out of service.
A senior Bush administration official said that under the deal, the United States will dismantle some of its warheads and put the rest in storage. He says Russia, which originally called for destroying all the weapons, would likely follow a similar approach, and put some warheads on standby.
The official, who spoke to reporters on condition of anonymity, estimated that each side currently has between 5,000 and 6,000 operational strategic warheads. He said, under the deal, that number will drop to between 1,700 and 2,200.
Presidents Bush and Putin agreed to the nuclear reduction targets in principle last year. At first, Mr. Bush raised doubts about the need for a formal treaty, saying years of negotiations would delay cuts both sides were willing to impose anyway.
The president relented when it became clear negotiations could be concluded in months, not years. In all, they took about five or six months, and produced a lean, concise document that, according to the White House, runs just three pages. That is unusually brief for a nuclear arms deal.
The agreement focuses solely on offensive nuclear arms reductions, and does not touch the dispute over President Bush's plans to build a missile defense shield. It will go into effect as soon as it is ratified by the U.S. Senate and the Russian Duma.
But in truth, the nuclear arms reductions are already underway, or at least in the planning stages. When asked why a treaty is necessary when the United States is willing to move ahead unilaterally, the senior administration official stressed that it provides guarantees that the process will continue, no matter who is in charge in Washington and Moscow.