Kuwait still needs to do more to combat the financing of jihadists, a top Kuwaiti official said Monday at a meeting aimed at choking off funding for the Islamic State group.

"We still have a lot to do, though we are satisfied with what we have done so far," Deputy Foreign Minister Khaled al-Jarallah told reporters on the sideline of a meeting of the Counter-ISIL Finance Group (CIFG) in Kuwait City.

"We are ready to cooperate with our brothers and friends," he said, responding to US criticism of Kuwait and Qatar over their steps to cut the financing of jihadists.

Formed early last year, CIFG is led by the United States, Italy and Saudi Arabia and is made up of over 35 countries and four international bodies.

Jarallah said Kuwait "has come a long way in introducing legislation that controls the collection of (charity) donations", a suspected channel of funding extremists.

The CIFG takes a global approach to undermining the flow of funds to the jihadist group, according to Adam Szubin, US Treasury's acting Under Secretary on Countering the Financing of Terrorism.

Szubin said last week that the meeting in Kuwait City aims "to share information and continue developing and coordinating countermeasures against ISIL's (IS) financial activity worldwide".

He said the Treasury was working closely with Kuwait and Qatar in particular to strengthen the technical side of the fight against terrorism finance, but "there is room for improvement".

Szubin said the effort to choke off funding was showing some success.

IS fighters had been abandoning the fight "as their pay and benefits have been cut and delayed, in what ISIL members in Mosul are calling a 'recession'", he said, referring to Iraq's battle to recapture the city from jihadists.