The EU has warned the US of retaliatory measures if citizens of the 27-nation bloc are not granted visa-free entry within five months.

"No tangible progress has been made regarding the United States despite all efforts of the Commission and individual member states," European Union Justice and Security Commissioner Jacques Barrot said in the statement.

Washington's visa waiver program allows visitors to travel to the US for up to 90 days for business or pleas... >>>