Global air freight volumes saw a 2% year-on-year drop in March, reflecting subdued growth in world trade, according to demand growth data released by the International Air Transport Association (Iata).

This decline was exaggerated by the quarter’s comparison with a particularly strong start in 2015, when air freight volumes were boosted by the effects of the US West Coast seaports strike.

The most significant fall in demand was reported by carriers in the Asia-Pacific region and North America. Combined, these regions, which reported declines of 5.2% and 1.8% respectively, account for around 60% of global freight traffic.

“It is shaping up to be another tough year for air cargo. February 2016 world trade volumes were only 0.4% higher than at the end of 2014,” said Iata director-general and CEO Tony Tyler, further noting that purchasing managers’ expectations showed little optimism for an early uptick.

“The combination of fierce competition, capacity increases and stagnant demand makes this a very difficult environment in which to generate profit,” he added.

In contrast, freight capacity rose by 6.9% year-on-year, putting increased pressure on already struggling yields.

African airlines saw a 3.1% drop in demand in March year-on-year, despite a more modest decline of 1.6% in the first quarter. Notably, Africa’s available freight tonne kilometres surged by 22% year-on-year in the first quarter, on the back of long-haul expansion, which was more than double the pace of any other region.

Asia-Pacific carriers saw a 5.2% drop in demand year-on-year, exaggerated by the effects of last year’s US seaport disruption, which fuelled strong demand for the region’s carriers. Nonetheless, demand was weak in this region, with export volumes from emerging Asian economies having contracted for 11 of the past 12 months.

Latin American carriers saw demand decrease by 5.9% year-on-year, with volumes now almost 15% lower than their seasonally adjusted peak in late 2014. The hardest hit routes were those within South America, which reflected the region’s challenging economic environment, particularly in Brazil.

North American airlines saw demand fall by 1.8% year-on-year, partially due to the roll-over effect of the 2015 US ports strike. Addi- tionally, the region’s carriers were negatively impacted on by the drop in global trade, while the strong US dollar was keeping exports under pressure.

Meanwhile, Middle Eastern and European carriers saw a year-on-year increase in demand of 2.4% and 1.3% respectively.

Growth in the Middle East, however, was the slowest since July 2009, reflecting a slowdown in network expansion by the region’s main carriers over the past six months, compounded by weak trading conditions.