Detailed Instructions: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Q: Passage: The Byelorussian SSR was one of the two Soviet republics that joined the United Nations along with the Ukrainian SSR as one of the original 51 members in 1945. After the dissolution of the Soviet Union, under international law, Belarus became the internationally recognized successor state to the Byelorussian SSR, retaining its UN membership.
Belarus and Russia have been close trading partners and diplomatic allies since the breakup of the Soviet Union. Belarus is dependent on Russia for imports of raw materials and for its export market.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.On 11 December 2007, reports emerged that a framework for the new state was discussed between both countries. On 27 May 2008, Belarusian President Lukashenko said that he had named Russian Prime Minister Vladimir Putin the "prime minister" of the Russia-Belarus alliance. The significance of this act was not immediately clear; some incorrectly speculated that Putin would become president of a unified state of Russia and Belarus after stepping down as Russian president in May 2008.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.
A:
The union of which two countries has been placed in doubt because of repeated delays of monetary union?