The union of Russia and Belarus, a supranational confederation, was established in a 1996–99 series of treaties that called for monetary union, equal rights, single citizenship, and a common foreign and defense policy. However, the future of the union has been placed in doubt because of Belarus's repeated delays of monetary union, the lack of a referendum date for the draft constitution, and a dispute over the petroleum trade.  Belarus was a founding member of the Commonwealth of Independent States (CIS). Belarus has trade agreements with several European Union member states (despite other member states' travel ban on Lukashenko and top officials), including neighboring Latvia, Lithuania, and Poland. Travel bans imposed by the European Union have been lifted in the past in order to allow Lukashenko to attend diplomatic meetings and also to engage his government and opposition groups in dialogue.