The outlook for business travel over the next year remains subdued and airfares will remain broadly static according to a new report.

The forecast by American Express Global Business Travel (GBT) said the geopolitical landscape and increased security concerns are causing global economic uncertainty.

The slowing Chinese economy, the UK’s vote to leave the European Union and security concerns in many countries have contributed to the uncertainty, the report says.

In the United States, airline overcapacity and strong competition between low cost and legacy carriers are creating a lower fare environment with US short-haul ticket prices forecast to fall 3 percent and long-haul by 1.5 percent in 2017.

The forecast for Canada is a 3.8 percent drop for short-haul and 3 percent for long-haul.

In Europe, muted economic performance, security concerns, pressure from Gulf carriers, and the continuing rise of low-cost carriers are contributing to the headwinds, GBT says.

The UK’s Brexit vote has had the effect of making outbound travel from Britain more expensive, dampening demand. The effect on UK airfares in 2017 is forecast to be a 2 percent drop in short-haul, and 3 percent for long-haul.

Airfares will stay flat across much of Asia-Pacific, with small increases depending on route and fare class, according to the report.