LONDON — The U.S. and its allies sought to put a good face on the coalition’s deliberate campaign to roll back the Islamic State group in Iraq and Syria on Thursday, boasting of having killed thousands of militants while acknowledging that ousting the group from key cities remains a distant aspiration.

Speaking to reporters in London alongside the British foreign minister and Iraqi prime minister, U.S. Secretary of State John Kerry said nearly 2,000 air strikes had arrested the Islamic State group’s momentum, squeezed its finances, killed “in the single digit” thousands of fighters and eliminated half of the group’s leadership.

A U.S. Central Command official said a conservative estimate would be 6,000 militants killed. The official was not authorized to discuss the matter publicly, and so spoke on condition of anonymity.

Kerry’s remarks came as Iraqi Prime Minister Haider al-Abadi told The Associated Press a day before the London meeting that the U.S. and its partners weren’t moving fast enough in supplying Iraq with weapons.

“There is a lot being said and spoken, but very little on the ground,” al-Abadi told the AP.