Relations between the world's reining and former superpowers have soured in recent days, signaling continued differences over nuclear weapons reduction and human rights.

Delegations for both the United States and Russia, meeting at the Pentagon this week to discuss details of an arms reduction deal announced by President Bush in November, have so far agreed only on the creation of joint committees that will work out the exchanges of data and information concerning the war on terrorism.

Under the surface is a distinct sense that the Russians are still peeved about Bush's scuttling of the 1972 Anti-Ballistic Missile Treaty in favor of moving forward with a new ambitious missile defense system. To codify their disappointment, members of the lower chamber of Russia's Parliament voted to condemn the U.S. withdrawal from the treaty on Wednesday.

To add fuel to the fire, Russia's foreign minister renounced publicly Bush's plan to reduce the U.S. arsenal of nuclear warheads in reserve rather than destroying them.

Douglas Feith, the undersecretary of defense who is leading this week's delegation, called the foreign minister's complaint a "red herring" Wednesday.

He said many of the cherished arms control treaties of the past also reduced weapons arsenals but did not specifically require their elimination.

The two sides are committed to major reductions in the arsenals of their strategic nuclear weapons. Bush pledged to cut back to 1,700 and 2,200 long-range warheads from the current U.S. level of about 7,000. Russian President Vladimir Putin said Russia, which has about 6,000 strategic warheads, would respond in kind.

Wednesday, Russian delegation head Col. Gen. Yuri Baluyevsky repeated the foreign minister's call that the warheads dismantled from the launchers be eliminated altogether.

Standing alongside Feith in a winter chill outside the Pentagon, Baluyevsky said cutbacks must be made "irreversible."

Feith did not respond to the demand but said the United States would codify any understanding in "the kind of document that is appropriate," reflecting the Bush administration's acknowledgment of Russia's desire for a formal treaty.

The goal of this week's summit is to design a set of "understandings for action" by Bush and Putin for their upcoming spring meeting in St. Petersburg, Russia.

The Associated Press contributed to this report.