Russia’s ground forces on Thursday crossed into Ukraine from several directions, Ukraine’s border guard service said, hours after President Vladimir Putin announced the launch of a major offensive.
Russian tanks and other heavy equipment crossed the frontier in several northern regions, as well as from the Kremlin-annexed peninsula of Crimea in the south, the agency said.
It said one of its servicemen died in a shelling attack along the Crimean border, the first officially confirmed military death of the Russian invasion.
Ukraine has suffered heavy casualties in its eight-year conflict with Russian-backed rebels in the separatist east, but has reported no fatalities along its southern border with Crimea for some years.
Russian President Vladimir Putin launched a military operation in Ukraine on Thursday with explosions heard across the country and its foreign minister warning a “full-scale invasion” was underway.
Weeks of intense diplomacy and the imposition of Western sanctions on Russia failed to deter Putin, who had massed between 150,000 and 200,000 troops along the borders of Ukraine.
“I have made the decision of a military operation,” Putin said in a surprise television announcement that triggered immediate condemnation from US President Joe Biden and other Western leaders, and sent global financial markets into turmoil.
Shortly after the announcement, explosions were heard in Ukraine’s capital, Kyiv, and several other cities, according to AFP correspondents.
Ukrainian border guards reported being under attack along the Russian and Belarusian frontiers.
Ukraine’s President Volodymyr Zelensky declared martial law and said Russia was attacking his country’s “military infrastructure”, but urged citizens not to panic and vowed victory.
His foreign minister said the worst-case scenario was playing out.
“Putin has just launched a full-scale invasion of Ukraine. Peaceful Ukrainian cities are under strikes,” Dmytro Kuleba tweeted.
“This is a war of aggression. Ukraine will defend itself and will win. The world can and must stop Putin. The time to act is now.”
Within a few hours of Putin’s speech, Russia’s defence ministry said it had neutralised Ukrainian military airbases and its air defence systems.
In his televised address, Putin justified the operation by claiming the government was overseeing a “genocide” in the east of the country.
The Kremlin had earlier said rebel leaders in eastern Ukraine had asked Moscow for military help against Kyiv.
Biden, who had for weeks sought to lead a Western alliance to deter Putin from invading Ukraine, spoke with Zelensky after the Russian operation began to vow US “support” and “assistance”.
He also vowed Russia would be held accountable.
“President Putin has chosen a premeditated war that will bring a catastrophic loss of life and human suffering,” he said in a statement.
“Russia alone is responsible for the death and destruction this attack will bring, and the United States and its allies and partners will respond in a united and decisive way.
Biden was due to join a virtual, closed-door meeting of G7 leaders — Britain, Canada, France, Germany, Italy, Japan and the United States — on Thursday.