A Donald Trump victory in the US presidential election this year could prompt the world economy to fall back into recession, according to Citigroup.

A team lead by the banking multinational's chief economist Willem Buiter has published a research note calling the showdown between Trump and Hillary Clinton a major source of economic uncertainty.

While it has a Clinton victory as the base case, with the forecast that her administration could bring about a major financial expansion, Republican success would spell bad economics news in the eyes of Citigroup.

"A Trump victory," the note reads, "Could lower global GDP growth by around 0.7-0.8%, pushing GDP growth easily below our benchmark for a global recession."

Citigroup is presuming increased uncertainty and tighter US financial conditions will accompany Trump in the White House.

The note defined recession as denoting world GDP expansion of 2% or less at market exchange rates.

The International Monetary Fund put global growth at 3.1% for 2015 and forecasts growth of 3.4% this year.

Trump himself unveiled a new economic plan for the US earlier this month, plotting new tariffs on Chinese goods, re-negotiations over international trade rule and offering tax incentives aimed at bringing American companies who operate abroad back home.

He has claimed that his policies will double US economic growth calling 4% "easily attainable".

The US Commerce Department today announced GDP of 1.1% for the second quarter.