Brussels, 20/06/2006 (Agence Europe) - With the EU-US Summit taking place in Vienna on Wednesday, the European Commission is threatening retaliatory measures to force the United States to exempt nationals from the EU Member States, including nine new Members, for the requirement to obtain a visa. In a letter dated 12 June and addressed to US Secretary of State Condoleezza Rice and Secretary of the Department of Homeland Security Michael Chertoff, the Commission says it might consider retaliatory measures, if no effort is made by the United States. These measures, a European source says, could go as far as to introduce visas for holders of diplomatic and official passports. The letter, signed by Commissioners Franco Frattini and Benita Ferrero-Waldner, calls on US authorities to make progress towards reciprocity of visa rules between the EU and the US. The fifteen “old” Member States, with the exception of Greece, are part of the “visa waiver scheme”, which allows their nationals to enter the US without a visa. The ten new Member States, apart from Slovenia, are still not part of the scheme. The American government regularly says that it is examining the possibility of including them in the scheme, but things have not advanced despite promptings from the EU. US citizens, on the other hand, can enter the EU without a visa. “We are very hopeful that the United States will realise the impact of their position,” said a European source, who characterised the American attitude as “discriminatory in the eyes of EU citizens”. Were the EU to take sanctions, they would probably be limited to diplomats and official staff since imposing visa requirements on American citizens wanting to visit the EU would be counter-productive. The introduction of visas for certain categories of people, however, could be approved by majority decision in the Council. Such a measure would not apply to the United Kingdom or Ireland, since they are not members of the Schengen zone. At the JHA Council in February, EU interior ministers asked the Commission to show, in a report to be submitted in July, the progress made towards visa reciprocity with the United States, Australia and Canada, as well as possible measures that could be taken against each of the three countries if there were to be no effective reciprocity.