GENEVA (REUTERS) - Global economic growth will quicken to 2.7 per cent this year and 2.9 per cent in 2018, after growing by 2.2 per cent in 2016, the United Nations said in its annual economic forecast on Tuesday (Jan 17).

However it saw uncertainty created by Britain's vote to leave the European Union, and British growth is expected to slump from an estimated 2.0 per cent in 2016 to 1.1 per cent in 2017 and 1.3 per cent in 2018.

Tax policies espoused by US president elect Donald Trump could also have adverse effects on the world economy, said Alfredo Calcagno, head of macroeconomic and development policies at the UN economic agency UNCTAD.

"This might generate a deficit in the short run and that could bring us towards a challenge for the global economy," he told a news conference in Geneva.

"The other element of tax reform is whether this tax system would mean a kind of higher protection for American producers. Then this would incorporate a huge challenge for the multilateral system and the WTO."