Normalizing Russia-US relations to improve situation in Central Europe -- top diplomat / Russian-US meetings have not yet taken place -- Russian diplomat / Good Russia-US relations key to global stability -- RDIF chief / Moscow notes West's nervous reaction to Russia-US contacts -- diplomat / Russian official highlights global importance of Russia-US relations / Russia-US relations on brink, nuclear control declines -- Russian senior diplomat / Russia-US relations on 'verge of rupture' -- senior diplomat / Russia-US relations unlikely to thaw despite Trump's plans to meet with Putin -- expert / US threatens Russia-friendly countries with secondary sanctions -- Russian Ambassador / US seriously engaged in 'hunting Russia's friends' -- Russian senator