Qatar, a key Arab partner in the U.S.-led coalition to take on the Islamic State (IS), believes that the coalition is "not doing enough" to fight the terror outfit, Qatari officials said.
Officials stressed on the need to accelerate and expand the training of moderate rebels, reported the CNN.
The U.S. is still in the process of vetting moderate rebel groups.
Qatari officials, who are in Washington to meet President Barack Obama and lawmakers on Capitol Hill, also emphasized on the need for the coalition to expand its operation to target President Bashar al Assad's forces, a step that U.S. has refused to take despite seeking the removal of Assad several times.
They said that U.S. and its allies should at least prevent Assad's troops from using barrel bombs on civilians. Obama's failure to enforce his own red line following Syria's use of chemical weapons has damaged U.S.' credibility in the region, the official noted.
The U.S. has had its own disagreements with Qatar. It has accused the Persian Gulf state of providing financial assistance to extremists in Syria and allowing Qatari individuals to pour money to some of the most extreme terror networks, including Al Qaeda-linked Nusra front.
U.S. and Arab officials have recently credited Qatar with reducing its support.