MOSCOW (REUTERS) - Russia will "respond" if Russian citizens start being killed anywhere, including in Ukraine's rebel Donbass region, Russia's RIA news agency cited Russian envoy to the European Union, Mr Vladimir Chizhov, as saying on Tuesday (Feb 15).

"We will not invade Ukraine unless we are provoked to do that," Mr Chizhov said.

"If the Ukrainians launch an attack against Russia, you shouldn't be surprised if we counterattack. Or, if they start blatantly killing Russian citizens anywhere - Donbass or wherever."

The Moscow-backed rebels say the Kyiv government is preparing an offensive against them, while Ukraine says Russia, which has amassed over 100,000 troops close to Ukrainian borders, is planning to invade its neighbour.