Russia has warned Ukraine could lose its statehood.

Nikolai Patrushev, secretary of Russia’s Security Council, said authorities of the former Soviet republic are being “controlled” by the West, warning it stands to lose its independence and identity as a consequence.

“The continuation of such policy by the Kiev authorities can contribute to the loss of Ukraine’s statehood,” Mr Patrushev told Rossiyskaya Gazeta, according to Russian news agency Tass.

“The Kiev authorities are doing everything to split Ukraine, implementing the West’s scenario to break Ukraine away from Russia, while ignoring the interests of its own people.

“As a result, the country has been de facto split.”

UKRAINE-RUSSIA CRISIS DEEPENS

A crisis is continuing to unfold between Ukraine and Russia, following the latter's 2014 invasion and annexation of Crimea, an autonomous region in Ukraine’s southeast.

Over 10,000 people have been killed since the unrest began, with the conflicting sides largely locked into a stalemate.

Last November, three Ukrainian vessels and 24 Ukrainian soldiers were fired at and captured by Russian coast guards in the Black Sea, exacerbating tensions between the two countries.

The incident marked the most dangerous direct clash in years between the ex-Soviet neighbours.

Yesterday, Russia extended the detention of the captured Ukrainian sailors despite protests from Kiev and the West, defence lawyers said.

Moscow’s Lefortovo district court extended until at least April 24 the arrest of a dozen of the soldiers, including their commander Denys Grytsenko, AFP reported.

The other 12 were expected to be ordered to remain behind bars.

Western diplomats, Ukraine’s top rights official Lyudmila Denisova and the sailors’ relatives were present in court.

The US embassy in Ukraine urged Russia to let those detained walk free. “Russia must release Ukraine’s sailors immediately, not use them as political pawns,” it said.

“For over 50 days, Russia has unjustly detained Ukrainian sailors who were exercising Ukraine’s freedom of navigation in its territorial waters. We are deeply concerned about their health and rights.”

The 24 Ukrainian crew members were detained, and three of them were wounded. The wounded sailors currently undergoing treatment in pre-trial detention in Russia also appeared in court.

Ukrainian President Petro Poroshenko has insisted the sailors are “prisoners of war” and should be immediately released.

Russia has said the sailors will go on trial for violating its maritime borders. They face up to six years in prison for illegally crossing Russian borders, lawyers have said.

Critics of the Kremlin have warned that Russia is preparing a show trial.

Russia has also slammed the United States for its role in the conflict. The US has provided over $US1 billion to Kiev’s defence military capabilities, and last year co-hosted a major exercise with US Navy warships.

“The population of the western regions does not trust natives of southeast, considering them to be supporters of the ‘Russian world’,” Mr Patrushev said.

“In southern and eastern regions, Kiev’s power is ensured, to a large extent, at the expense of moral and physical pressure exerted on the local population by radical nationalists.

“Because of that, anti-government sentiment in the aforementioned regions is mounting, with the public rift exacerbated by the inter-church standoff,” he concluded.

UKRAINE SHOULD ‘EXPECT THE WORST’

Experts have warned that Ukraine should be prepared to expect “the worst” as we head into 2019.

Last month, satellite photos revealed a build-up of Russian forces on the Ukraine border, increasing fears of invasion.

According to Ukrainian media reports, commercially-available satellite photos revealed several heavy IL-76 cargo aircraft flying into the Dzhankoi air base in occupied Crimea.

Anders Åslund, a senior fellow at the Atlantic Council, said the country’s new elections are viewed by the Kremlin as a direct threat.

“Russia has made it abundantly clear that it is not intent to make any progress in the Minsk negotiation process in 2019, leaving open what will happen later on,” he wrote.

“Most important is that the new elections in Ukraine are a major threat to Putin’s authoritarian kleptocracy in Russia.

“If Ukraine succeeds in holding democratic elections, Putin will feel seriously threatened, as democracy is apparently possible in an orthodox and East Slavic country.

“Therefore, Ukraine should expect the worst from Russia in 2019.”

He noted that the political effect of economic sanctions on Russia have “probably been exhausted”, and that Moscow will soon have to resort to other measures, including “sheer terrorism”.

“The best Ukraine can hope for in 2019 is no further deterioration in its terrible relationship with Russia,” Mr Åslund wrote.

— with AFP