ANKARA, Turkey (AP) — Even as it discouraged Iran from joining diplomatic talks on how to defeat the Islamic State militant group, the United States could not outline Friday what other nations have volunteered to contribute to a worldwide effort against the insurgency that has overtaken a third of Iraq and Syria and threatens to upend the Mideast.

Secretary of State John Kerry, in Turkey to press its leaders on hardening its borders against extremist traffic and funding, said it’s not appropriate for Iran to be at the discussions, given its support for the very government in Syria whose brutality helped fuel the Islamic State group.