A senior commander from the self-styled Islamic State militant group was targeted and killed in a US operation, according to US Defense Secretary Ash Carter.

Mr Carter made the announcement at a Pentagon briefing this afternoon.

Abd ar-Rahman Mustafa al-Qaduli, the militant group's second-in-command, was killed in a raid in Syria yesterday.

The commander, who went by several aliases and was a senior religious leader within the militant group, was killed in a US air strike, according to Mr Carter.

T"he removal of this ISIL leader will hamper the ability for them to conduct operations inside and outside of Iraq and Syria," Mr Carter told reporters, referring to him as Haji Imam and saying he served as finance minister for the group.

The US Defense Secretary also discussed the death of another top IS leader, senior operative Abu Omar al-Shishani, in another recent strike.

A news agency that supports Islamic State has denied that al-Shishani, also known as the Chechen, had been killed or wounded.