Diplomats said on Monday the move, made through direct contacts between Washington and some EU countries including Greece and the Czech Republic, has annoyed the bloc's executive and a number of European capitals, as talks on air security have so far been conducted at a global EU-US level.

'The United States wants air marshals to be allowed on board US carriers flying to or from the US,' an EU diplomat said referring to a memorandum of understanding he said was sent by Washington.

Another European diplomat said: 'The United States also wants to extend the number of data in the Passenger Name Record', referring to a deal under which European air carriers send US authorities 19 pieces of information on air passengers 72 hours before departure.

'We are actively engaged with a number of European countries as well as the EU on our anticipated way forward when it comes to reforming the visa waiver programme,' said a spokesman for the US Department of Homeland Security. 'We're over there and we're meeting with a number of European counterparts.'

He said the role of US air marshals was usually worked out with individual countries.

The second European diplomat said the extra security measures, which would also include a form that all air travellers would have to fill in on the Internet, were a condition set by Washington to add individual EU countries to the United States' visa-free programme.

A senior US official said this month the United States could scrap visa requirements for Czechs, Greeks and Estonians by the end of this year, soon after the Internet travel authorisation system is implemented in August or September.

Eight mostly ex-communist countries that joined the European Union in 2004 have, along with previous EU member Greece, long pressed Washington to include them in the visa waiver programme enjoyed by Western European states.

Diplomats said ambassadors from the bloc's 27 member states would discuss on Wednesday how to react to what some saw as an attempt by Washington to bypass the EU and get more out of deals with individual countries.

'They are clearly trying to bypass the EU,' one said.

A spokesman for the EU's executive Commission, Mr Friso Roscam Abbing, declined to comment on the US demands but said: 'Visa policy is a community policy managed by the (European) Commission.'

The Czech Republic's Deputy Prime Minister in charge of European Affairs Alexandr Vondra confirmed talks were going on and said his country was not breaking ranks with EU solidarity.

'The Czech-US talks are being conducted in such a way that we do not violate any EU obligations,' he said on Monday, as quoted by a Czech diplomat in Brussels. The diplomat declined to give details on the talks. -- REUTERS