Kuala Lumpur, Malaysia: President Barack Obama said on Sunday that he had ordered his senior defence officials to find out whether intelligence reports had been altered to reflect a more optimistic assessment of the US military campaign against the Islamic State.

Speaking at a news conference in Malaysia at the end of a 10-day overseas trip, Mr Obama said he expected the Pentagon's inspector general to investigate allegations that significant changes were made to reports from analysts at the US Central Command, known as CENTCOM.

"I don't know what we'll discover with respect to what was going on in CENTCOM," Mr Obama said. "What I do know is my expectation – which is the highest fidelity to facts, data, the truth."

Mr Obama was responding to a report in The New York Times on Sunday that described the internal Pentagon investigation. Some analysts in the Defence Department say their supervisors revised their conclusions about some of the military's failures before finalising the reports.