The Vatican's secretary of state says there is "positive momentum" behind the idea of Pope Francis visiting Russia, but suggests there is more work to be done if it is to occur.
Cardinal Pietro Parolin made the comments on August 22 at a joint press conference with Russian Foreign Minister Sergei Lavrov in Moscow.
He did not give any prospective date for a possible visit by Pope Francis. It would be the first such trip by a pontiff in the modern era.
Francis, leader of the world's 1.2 billion Catholics, has sought to bridge enduring tensions between the Orthodox and Roman Catholic branches of Christianity, including with a landmark February 2016 meeting in Cuba with Patriarch Kirill, the head of Russian Orthodox Church.
Parolin also said that he raised certain difficulties faced by the Catholic Church in Russia during his talks in the Russian capital, and that Moscow and the Vatican disagreed about the plight of Christians in certain parts of the world. The cardinal did not elaborate.
Parolin also said that he believed Moscow could play an important contribution in helping solve the crisis in Venezuela because of its close ties with Caracas.
The South American country has been the scene of violent protests against President Nicolas Maduro's moves to increase his power and silence the opposition. The unrest has left more than 120 people dead since April.
Parolin was to meet Kirill later on August 22 and hold talks with President Vladimir Putin in the Black Sea resort of Sochi on August 23.
The discussion with Putin will include relations between Russia and the Vatican as well as "the plight of Christians in the Middle East and North Africa, the situation in Syria and Ukraine," the Kremlin said.
During his meeting with Putin at the Vatican in June 2015, Francis urged the Russian president to commit himself to a "sincere and great effort" for peace in eastern Ukraine, where fighting between government forces and Russia-backed separatists has killed more than 10,000 people since April 2014.