ABOARD AIR FORCE ONE (Reuters) - The United States has seen initial signs that Russia is withdrawing some of its forces from Georgia but Moscow is not moving fast enough, the White House said on Wednesday.

"It is not significant and it needs to increase," White House spokesman Gordon Johndroe told reporters aboard Air Force One as President George W. Bush flew to Florida to give a speech on terrorism.

"Both the size and pace of the withdrawal needs to increase and needs to increase sooner rather than later," he said. "I don't think they need any more additional time."

Johndroe said Moscow, which has been a key U.S. partner in trying to convince Iran and North Korea to give up their nuclear programs, was risking its standing in the international community with its actions in Georgia.

"We have wanted Russia to be a part of the greater international community," Johndroe told reporters. "Russia is making a decision and we certainly hope that it's not a long-term strategic decision, but Russia's making a decision that's only isolating itself."

He also said Russia was already feeling the repercussions of its incursion into Georgian territory, pointing to the agreement signed earlier on Wednesday to set up parts of a U.S. missile defense shield in Poland.

"Countries in central and eastern Europe do not want to go back to the way things used to be," Johndroe said. "They cherish their freedom and they are not interested in their neighbor invading them."