A rebel leader in east Ukraine on Wednesday challenged President Petro Poroshenko to a duel, claiming it could bring peace to the war-torn region.

Igor Plotnitsky, the 50-year-old leader of the self-proclaimed Lugansk People's Republic, wrote an open letter to Poroshenko suggesting the whole nation could even watch the duel on live TV.

"Each party has the right to ten witnesses and ten media representatives. I would not be against the duel being shown live on TV. I will let you choose the place and the weapons," Plotnitsky wrote.

"What is the point of hatred, killing people, destroying the economy and towns?... It would be better to resolve it with an honest duel and save, at the cost of one's life, the lives of millions of people."

The conflict between pro-Russian separatists and Ukrainian forces in the east has claimed over 4,100 lives in seven months, according to the United Nations.

Yevhen Perebyinis, a spokesman for the Ukrainian foreign ministry, wrote on Twitter in response that Plotnitksy was "worthy of only one duel: with Ukrainian justice".

Plotnitsky was elected leader of the Lugansk People's Republic earlier this month in Russian-backed elections which were described by Kiev as a "power grab" and condemned by the West.

He is accused by the Ukrainian government of having overseen the transfer to Russia of Ukrainian military helicopter pilot Nadia Savchenko earlier this year.

Kiev says Savchenko was abducted from Ukrainian territory and taken to Russia, while Moscow insists she was arrested after crossing the border illegally.