US aircraft maker Boeing sees 28,600 new aircraft worth US$2.8 trillion being sold over the next two decades owing to rising global airfreight and passenger demand.

But Boeing also expressed fears of coming government curbs on travel due to environmental concerns that might retard growth too.

This year's Boeing forecast exceeds last year's figure of 27,210 new planes by 2025, due to the inclusion of the Russian market, Boeing said. The company predicts the world airlines will be flying 36,400 passenger and cargo planes by 2026 - doubling today's 18,200.

Boeing expects 6.1 per cent annual growth in cargo and five per cent more passengers till 2026. Last year, Boeing saw the same cargo growth rate, but a slightly lower 4.9 per cent annual increase in passengers.

North America would make up 26 per cent of sales. Europe, including Russia and other members of the Commonwealth of Independent States, would buy another 25 per cent. Russia and other CIS members would alone account for 1,060 new planes, valued at $70 billion. Latin America, the Middle East and Africa are expected to fly the remaining 13 per cent.