Trump has criticized the United States government's opposition to the Syrian President Bashar Assad in the context of the fight against Daesh.

MOSCOW (Sputnik) — US Republican presidential candidate Donald Trump has criticized the United States government's opposition to the Syrian President Bashar Assad in the context of the fight against Daesh (ISIL).

"Well, I thought the approach of fighting Assad and ISIS simultaneously was madness, and idiocy. They’re fighting each other and yet we’re fighting both of them. You know, we were fighting both of them. I think that our far bigger problem than Assad is ISIS, I’ve always felt that," Trump said during Saturday's interview with The New York Times newspaper.

Trump has been vocal about his views on changing US foreign policy in the course of the ongoing Republican Party presidential primaries ahead of the 2016 US presidential election. The Republican frontrunner has previously called on the terms of US membership in NATO to be changed, as well as calling on the alliance to shift its focus to countering terrorism.

Daesh gains much of its revenue from oil and from banking channels, Trump said, stressing that both of these have to be targeted in order to undermine the militants.

Daesh funds comes via sophisticated banking operations from those the US government perceives as its allies, he added.

Syria has been mired in civil war since 2011, with government forces fighting numerous opposition factions and radical Islamists, including Daesh. Most Western governments, including the US government, have been calling on Assad to step down since the start of the conflict.

Daesh is a militant jihadist group, which is outlawed in many countries, including the United States and Russia.