The US has criticised President Lukashenko's authoritarian regime

The decision was also prompted by US sanctions imposed on the country's state-controlled oil-processing and chemicals company, Belneftekhim.

The Belarusian Foreign Ministry announced at the same time that it was recalling its own ambassador to the US.

A White House spokesman described the expulsion as "deeply disappointing".

The United States - along with the European Union - has restricted the travel of authoritarian President Alexander Lukashenko and members of his inner circle, as well as imposing economic sanctions.

We strongly regret this unjustified action by the Belarusian government. This is deeply disappointing and only takes them further away from Europe and the rest of the world

Gordon Johndroe, White House spokesman

Both the US and the EU have demanded that President Lukashenko frees political prisoners, and allows more democratic regimes, before normal relations can be restored.

Mr Lukashenko has signalled that it would like better relations with the West, after Russia decided on a large increase in the prices of its oil exports to Belarus - which it relies on heavily.

Pressure from Washington

Some opposition activists were released this year, a move which was welcomed by the US State Department.

But there has been no response to pressure from Washington to release Alexander Kozulin, who challenged Mr Lukashenko in the 2006 presidential election, and was arrested during a post-election protest.

Mr Kozulin was allowed to attend his wife's funeral, but then put back in prison.

The United States said the expulsion of its ambassador, Karen Stewart, further isolated Belarus from the West.