By Anna Voitenko
KYIV (Reuters) -Finland's president on Wednesday signed a 10-year security deal with Ukraine in Kyiv where President Volodymyr Zelenskiy said he believed Russia planned to mobilise 300,000 new troops for its war by June.
But Kremlin spokesman Dmitry Peskov, quoted by Russian news agencies, said the Ukrainian president's assertion about a new Russian mobilisation was untrue.
The pact signed by President Alexander Stubb and Zelenskiy made Finland the eighth NATO member this year to commit to long-term security cooperation and defence backing for Kyiv as it battles to hold back Russian forces.
Finland, which shares a 1,340-km (830-mile) border with Russia, joined NATO a year ago.
Stubb said Finland would also send 188 million euros ($203 million) in additional military aid, including air defences and heavy-calibre ammunition. That sum took Finland's overall defence contribution to around 2 billion euros during the war.
"We are not giving this military support only for Ukraine to defend itself, we are giving this military support for Ukraine to win this war," Stubb told a joint news conference in Kyiv.
Ukraine relies heavily on Western air defence systems and has faced a recent surge in Russian missile and drone attacks that have battered its energy system.
On the battlefield, Ukraine is on the back foot as military assistance from the United States stalls and Kyiv's troops find themselves outgunned by a larger and better armed foe. Russia has inched forward.
ZELENSKIY SAYS RUSSIA IS PREPARING
Though he provided no evidence to back up his assertion, Zelenskiy told the news conference: "I can say that Russia is preparing to mobilise 300,000 military personnel by June 1."
And later, in his nightly video address, Zelenskiy said: "We clearly understand what Russia is preparing for, what they want, what they want to assemble soldiers for in their army."
He said he had discussed plans and tactics with Ukraine's top military commander, Oleksandr Syrskyi, including "defending out positions, our pressure on Russian positions, our key plans for defensive and offensive actions in the near future".
Russian President Vladimir Putin denied in December that there was a need for Moscow to conduct another wave of mobilisation, something that would be politically sensitive.
On Wednesday, the Russian defence ministry said more than 100,000 people had signed contracts with the army since the start of the year, including about 16,000 in the past 10 days following a deadly attack on a concert hall near Moscow.
Zelenskiy's comments come as the Ukrainian parliament considers an overhaul of the rules governing how Ukrainian civilians are called up into the army.
This week, Zelenskiy signed legislation reducing the draft age to 25 from 27, expanding the number of people who can be called up to fight.
At the news conference, he said he did not think Ukraine needed to mobilise as many as 500,000 more people into the army, an idea floated late last year, but that he did not know yet how many were needed.
(Reporting by Louise Breusch Rasmussen in Copenhagen and Yuliia Dysa in Gdansk; Editing by Stine Jacobsen, Mark Heinrich, Nick Macfie, Sharon Singleton, Ron Popeski and Alison Williams)