Ukrainian prime minister Arseny Yatsenyuk has accused last Friday Russia of trying to start World War III with its actions in Ukraine. Yatsenyuk said Russia aims to occupy Ukraine "militarily and politically" and spark a war in Ukraine that "will lead to a military conflict in Europe."

Yatsenyuk was speaking to his cabinet on Friday, 25 April, in remarks broadcast live.

His comments came as acting defense minister Mykhailo Koval said Russian troop maneuvers have come within one kilometer of Ukraine's border, adding that Ukraine's armed forces stand "ready to repel any aggression."

Moscow says it is simply conducting military exercises. Russian Foreign Minister Sergei Lavrov has accused Washington of distorting an international agreement on Ukraine by making additional demands on Moscow.
 
Speaking in Moscow on April 25, Lavrov said "one-sided demands" are being made by the United States, which he insisted has "an outstanding ability to turn everything on its head."
 
He also said the pro-Western government in Kiev will eventually face justice for its security operation in eastern Ukraine, calling it a "bloody crime."
 
Lavrov has accused the West of plotting to control Ukraine and said the pro-Russian insurgents in the southeast would lay down their arms only if the Ukrainian government clears out the Maidan protest camp in the capital Kiev.

"The West wants — and this is how it all began — to seize control of Ukraine because of their own political ambitions, not in the interests of the Ukrainian people," Lavrov said on Friday.

Lavrov's comments came after U.S. Secretary of State John Kerry said the "window of opportunity" for Russia to change course in Ukraine is closing.
 
Kerry said Russia has not taken "a single concrete step" to implement the agreement reached last week in Geneva.

On the ground, Russia announced new military exercises involving ground and air forces near its border with Ukraine, swiftly responding to a Ukrainian operation to drive pro-Russia insurgents out of occupied buildings in the east. 

Pro-Russian militias have been occupying government buildings in more than 10 cities in the eastern Ukraine, while the nationalist Right Sector movement is still in control of two public buildings in Kiev.

Moscow in March recognized a hastily called referendum in Ukraine's Black Sea peninsula of Crimea and annexed it weeks later, attracting condemnation of the West as well as sanctions targeting individuals. Kerry said that unless Moscow took immediate steps to de-escalate the situation, Washington would impose additional sanctions.

Russia's involvement in Ukraine is already hurting Russia's economy.

The Standard & Poor's credit agency on Friday cut Russia's credit rating for the first time in more than five years. The ratings agency's main concerns the flight of capital and the risk to investment in Russia since the Ukraine crisis blew up late last year.

Credit ratings are important for the economy because they determine the cost of borrowing on international markets. Russian Economic Development Minister Alexei Ulyukayev sought to play down the downgrade, calling it "partly politically motivated."

In southeastern Ukraine, seven people were injured early Friday by a blast at a checkpoint set up by local authorities and pro-Ukraine activists outside the Black Sea port of Odessa. Local police spokesman Volodymyr Shablienko said unknown men had thrown a grenade at the checkpoint.

The Odessa region has so far not been affected by the pro-Russian insurgency.

Vladimir Putin was also criticised by German Chancellor Angela Merkel. Merkel said she told President Vladimir Putin that further sanctions against Russia may be necessary because Moscow has not done enough to implement the Geneva agreement on de-escalation of the Ukraine crisis.

Merkel, speaking on Friday in Berlin after talks with Polish Prime Minister Donald Tusk, said Russia has "the power" to persuade pro-Russian separatists to leave government buildings they occupy in eastern Ukraine.