The International Civil Aviation Organization has set a goal of capping emissions from international aviation beginning in 2020 while gradually improving fuel efficiency.

The UN agency approved the "aspirational" goal, which is not binding on any of its 190 members, in a final resolution late Friday of a meeting here of its general assembly.

The organization also unanimously supported a comprehensive aviation security strategy that calls for identifying and preventing new forms of attacks, streamlined security checks, and helping states improve their capabilities in this area.

President Barack Obama issued a statement Saturday praising the security declaration as "a historic new foundation for aviation security that will better protect our world from evolving terrorist threats."

On the environmental side, IAOC reaffirmed a goal of improving fuel efficiency by an average two percent a year through 2050.

It also said its members agreed to "work together to strive to achieve a collective medium term global aspirational goal of keeping the global net carbon emissions from international aviation from 2020 at the same level."

The goal was not binding on any individual state and the resolution included a host of caveats such as the "special circumstances" of developing countries, the maturity of aviation markets and sustainable growth of the industry.

In a press release, the ICAO acknowledged that some member states expressed reservations about the resolution but said its passage nevertheless made ICAO the first UN agency to lead a sector in "a globally harmonized agreement for addressing its CO2 emissions."

"It is a major achievement," said Helen Kearns, spokeswoman for the European Commissioner for Transportation Siim Kallas.

"Contracting states will have to submit to ICAO how they intend to reach their target," she told AFP in Brussels.

"Second, it does not prevent anybody to go further and faster and acknowledges certain parties would do so," she said, adding "EU can go ahead."

Kearns said the resolution endorses a European plan for imposing a carbon emissions tax starting in 2012 on flights destined for or originating in Europe, which has drawn legal challenges from US airlines.

The International Air Transport Association also hailed the resolution as "historic."

"For the first time, we have globally agreed aspirational goals to stabilize emissions," said Giovanni Bisignani, IATA's director general. "This is a good first step that prepares the way for future achievements."