After low-key meetings in Washington, Bahrain's crown prince has made another promise of national dialogue.

But US President Barack Obama, although welcoming the end of emergency law, has made his position clear: "You can't have national dialogue if you keep locking up the opposition."

The US needs the Gulf state as a port for its Fifth Fleet and, as long as the price of oil remains high, the US cannot afford to annoy Saudi Arabia whose troops remain in Bahrain in support of the Sunni monarch.

Nearly three months since the crackdown began, hundreds of people including activists, students, teachers, hospital staff and member of the political opposition have been arrested. Bahrain insists it is only punishing criminals.

Al Jazeera's Charles Stratford reports.