European airports will keep restrictions on liquids carried onto aircraft for another three years because the roll-out of scanning technology is behind schedule, EU nations have agreed.

The 27 European Union nations have reached agreement to maintain the restrictions on carry-on liquids until April 2013, a European Council document showed Wednesday.

Under the agreement "all airports must have the capacity to screen those products by April 29, 2013."

European restrictions were imposed in November 2006 in the wake of plot to blow up transatlantic jets uncovered by British authorities.

Since then, creams, hair gels in pressurised cans and bottles of water, for example, have been unceremoniously binned by security staff if the containers hold more than 100 millilitres.

Even very small quantities must be taken on board in a transparent resealable plastic bags.

The rules apply at any airport within the 27-member European Union, plus Albania, Iceland, Kosovo, Norway, Russia, Serbia, Switzerland and Ukraine, irrespective of the destination.

The security measures were due to expire in April but it was judged that at least another year's work will be required before reliable new generation scanners are available.

Such machines will allow substances to be tested without removing them from their containers.