Russia has expanded its economic sanctions on Ukraine, adding more than 250 people and businesses to a blacklist first announced at the start of November.

According to a decree by Prime Minister Dmitri Medvedev, 245 individuals and seven companies, mostly in the energy and defence sectors, were sanctioned by Moscow.

Relations between Moscow and Kiev have deteriorated since a pro-Western government came to power after the 2014 revolt against a pro-Russian leader, Moscow's annexation of the Crimea and the outbreak of war in eastern Ukraine.

A total of 567 individuals and 75 Ukranian companies now face Russian economic sanctions, which put a freeze on any assets they have in Russia.

On his Twitter account, Mr Medvedev said the sanctions were "to defend the interests of the Russian government, businesses and people." 

Tensions between the two neighbours have worsened since November when Russia's coastguard captured three Ukrainian naval vessels and their crews off the Crimean coast.

Among those sanctioned today were Ukrainian defence, energy, insurance and logistics companies as well as Odessa's mayor and other high-ranking Ukraine officials.

Since the outbreak of the Ukraine war, Kiev has taken a series of measures against Russian interests, including blocking Russian internet services and social media.

The conflict pitting pro-Russian separatists against Ukrainian government forces is estimated to have claimed more than 10,000 lives - one third of them civilian - since it broke out four years ago.