The European Union's president says the bloc is ready to open talks with London on how it must change to keep Britain as a member.

EU President Donald Tusk said Friday that "we should consider British concerns, but only in a way that will be safe for all of Europe."

During an EU summit that ran into the early morning, Tusk said British Prime Minister David Cameron told fellow EU leaders about his plan to hold a binding nationwide referendum by 2017 that will ask British voters whether or not they want their country to remain in the EU.

Tusk said "the talks on U.K. renegotiation will now get underway." But he indicated it could be a long process. He said EU leaders will return to the issue in December.