COLOMBIAN President Gustavo Petro ordered the state-run oil company Ecopetrol to cancel a joint venture with a United States-owned company, citing environmental concerns on Tuesday.

In a nationally televised speech, Mr Petro said he opposed the recent extension of a deal between Ecopetrol and Occidental Petroleum because it involved extracting oil through fracking.

Fracking is a controversial technique, used to extract oil and gas from shale rock, criticised by many environmental groups for polluting water sources and causing earth tremors.