Britain's effort to leave or stay in the 28-member European Union, Turkey's incursion into northern Syria, and the bloc's enlargement all are expected to be on the agenda of the two-day EU summit on October 17-18 in Brussels.
The meeting of EU national leaders won't see the legal documents for a potential Brexit although British and EU negotiators reached an agreement for the country's departure, barring value-added tax regimes, on October 16.
Any eventual deal would also have to be approved by the British and EU national legislatures.
The EU's response to Turkey's invasion of northeastern Syria over the past week will be watched as the bloc has taken the symbolic step of limiting weapons deliveries to Turkey, leaving an EU-wide arms embargo as a more severe option.
Under a 2016 deal, Turkey has agreed to stem the tide of refugees from war-torn Syria and has housed about 3.6 million of them on its territory.
The 2021-27 budget will be discussed. Should Britain leave the EU, Brussels could see about $13.2 billion-$15.4 billion less in contributions each year.
EU expansion, including reforming the slow and arduous enlargement process, is another issue on the agenda. This week, Albania and North Macedonia were denied approval to proceed along the membership path.
Climate change and environmental benchmarks, like the 2050 target year for achieving net carbon neutrality, is a key discussion item.