BRUSSELS (AP) – The European Union and Britain kick off their first full session of their divorce proceedings with both sides bent on seeking a quick breakthrough on unraveling ties that have bound them for decades.

U.K. Secretary of State David Davis said at the start of the four-day session Monday that “it is incredibly important we now make good progress.”

The talks this week are set to center on the rights of citizens in each other’s nations post-Brexit, the bill Britain has to pay to meet existing commitments, the border issue in Ireland and the pre-eminence of the EU’s Court of Justice.

The two hope there will be sufficient progress on those issues this summer so that talks on a future relationship between the two can start in October or November.