"It's probably going to happen next week," the State Department official told reporters when asked about the issue.

"The president (George W. Bush) has to withdraw the document from Congress. So he needs to take that step, and that's what will happen."

The official, who spoke on the condition of anonymity, did not explicitly say whether the decision had already been taken to withdraw the pact.

The White House said August 28 that it was considering dropping the agreement.

The agreement aims to allow US and Russian companies to form joint ventures in the nuclear sector and gives the go-ahead for exchanges of nuclear technology between the two countries, according to officials on both sides.

Russia would also be able to reprocess spent nuclear fuel originating in the United States, which accounts for most of the world market, in a move that has raised fears of Russia being turned into a nuclear dump.

President Bush and his Russian counterpart at the time Vladimir Putin inked the agreement at a summit in Kennebunkport in the United States last year and discussed it again in the Russian resort of Sochi in July.

Asked if dropping the agreement could undermine efforts to stop the spread of nuclear technology, the State Department official said: "It's hard to predict.

"But again we've made very clear that Russia's behavior has to be condemned and there have to be consequences that flow from (its actions) in Georgia. This will be an example of that," he said.

"We want to work with Russia on a wide range of issues, but Russia has to show it's interested in working with the international community," he said.

"The fact there is a ceasefire ...that they're not adhering to is troubling to all of us and so we question just how closely we can work with Russia on a wide range of issues," he said.

"And that's why basically our relationship right now is being reviewed across the board," he said.

Russian troops poured into Georgia last month to repel an attack by the Georgian army aimed at retaking South Ossetia. They have remained deep inside Georgian territory in what Moscow calls "security zones."