MARRAKECH, Morocco (AP) — The U.S. and the head of the new Syrian opposition coalition being feted at a conference in Morocco Wednesday publicly disagreed over designating a rebel group as terrorist, highlighting a key dilemma in overthrowing President Bashar Assad's regime.

Even as the U.S., Europe and its allies recognized the new opposition of the sole legitimate representatives of the Syrian people to succeed the Assad regime, they have to deal with the fact that some of the greatest battlefield successes are by extremist groups the West does not want to see running the country one day.

The Obama administration designated Jabhat al-Nusra a terrorist organization Monday, a day before he recognized the newly formed Syrian National Coalition as the legitimate representatives of the Syrian people.