MOSCOW, October 25 (RIA Novosti) - The transition to a single currency is the most important condition for establishing a Russia-Belarus Union State, the Russian president said in a televised question-and-answer session Wednesday.

The two countries have been negotiating on a union state since they signed an agreement on April 2, 1997. The project sets out to establish common economic, customs and political regulations, but negotiations have stalled recently over a number of issues, including a Russian proposal to raise natural gas prices for Belarus.

"First, we need to speak about economic integration. In this area, I consider the transition to a single currency to be the key issue," Vladimir Putin said.

The president said Russia wanted to accelerate this process, and that economic issues were the priority.

"We are at the stage of harmonizing political issues, in particular the Constitutional Act. But I will say honestly and openly that the economy is still the priority. An economic base is required to establish, for example, a common parliament," Putin said.