The US government has unveiled emergency measures to avert a security meltdown at its airports this summer, amid fears that it could take travellers up to four hours to clear procedures at peak times.

Waits of one hour to pass through the country’s busiest hubs are becoming increasingly common, and delays of more than four hours have been recorded in Las Vegas. With forecasts of 200m travellers flying into and within the USA between July and September, the Transportation Security Administration (TSA) has come under intense pressure to reduce queueing times.

Last week, it announced that it would draft hundreds of staff from smaller bases to 25 of the most popular airports to cope with the anticipated demand.

Airports receiving additional screeners include John F Kennedy and Newark (which will get an extra 404 security officers, bringing its tally to 3,164), Dallas/Fort Worth (308), Miami (295), Orlando International (101) and Washington (100).

The TSA estimates that this will reduce delays at security checkpoints by up to 20%, keeping the average wait to between 12 and 30 minutes.

The TSA will also employ on-site “divestiture coaches” to give travellers tips on how to speed up their progress through the airport — removing jackets before arriving at the front of the line, for example, and packing sharp objects in luggage that will be checked in, rather than in hand baggage.

The precautionary steps come as the United States continues to reel from the adverse publicity that has greeted the enhanced security for entering the country. Estimates suggest that the new controls have led to a 30% decrease in foreign arrivals.

Holidaymakers are deterred by stories about long airport queues, confusion over new passport requirements and concerns about overzealous application of rules by immigration staff that have led to visitors being deported on minor technicalities.

On June 10, representatives of the British travel industry will visit the USA for talks on how further security requirements can be introduced with as little disruption as possible.