"At the moment, we only know that this should be a broader discussion about relations with Russia, not a discussion about sanctions," the source said.
Europe's anti-Russian individual and economic sanctions have been the main issue in bilateral relations between the two sides since the Ukrainian crisis erupted in 2014.
Brussels imposed several rounds of sanctions on Russia over Crimea's secession from Ukraine and Moscow's alleged meddling in the Ukrainian conflict. Russia has repeatedly refuted the accusations, and warned that the sanctions are counterproductive and undermine regional and global stability. The sanctions have been renewed numerous times since.