KYIV- Ukraine on Wednesday said Russia was likely behind the largest cyberattacks of their kind on the country, which downed the web portal of the defence ministry and disrupted banking and terminal services at large state-owned lenders.

The Kremlin has denied involvement in the distributed denial of service (DDoS) attacks, which hit Ukraine at a time when the country is bracing itself for a possible invasion after Russia massed more than 100,000 troops near its borders in recent weeks.

Ukraine has previously also accused Russia of launching cyberattacks to sow panic and crash its financial system.

"Yesterday, on February 15, the largest DDoS ??attack in the history of Ukraine was carried out on government websites, on the banking sector," Deputy Prime Minister Mykhailo Fedorov said in a joint briefing with senior officials.

"This attack is unprecedented, it was prepared in advance. And the key goal of this attack is destabilization, it is to sow panic, to do everything so that a certain chaos appears in our country."

llya Vityuk, Head of the Cybersecurity Department of the state security service (SBU), said it was too early to identify specific perpetrators.

But he added: "And today we know that the only country that is interested in such ... attacks on our state, especially against the backdrop of massive panic about a possible military invasion, the only country that is interested is the Russian Federation."

Fedorov said the attacks came from many places and involved IP addresses from Russia, China, Uzbekistan and the Czech Republic.

A senior central bank official said the hackers had succeeded in disrupting services at PrivatBank, the country's largest lender, but that the attacks did not cause any losses in the financial system. The hackers also targeted smaller banks in a second wave.

The hackers had also tried to attack the SBU systems but failed to do so.

(Reporting by Natalia Zinets; writing by Matthias Williams; Editing by Alex Richardson) ((;))