Russia said on Monday a decision by Denmark and the Netherlands to donate the first F-16 fighter jets to Ukraine would only escalate the conflict, while Ukraine said the jets would help end Moscow's invasion.
Denmark and the Netherlands on Sunday announced they would supply F-16s to Ukraine, with the initial six due to be delivered around New Year. Washington approved the delivery of the U.S.-made jets last week.
"The fact that Denmark has now decided to donate 19 F-16 aircraft to Ukraine leads to an escalation of the conflict," Russian ambassador Vladimir Barbin said in a statement cited by the Ritzau news agency.
Denmark is forcing an escalation: Russian ambassador
"By hiding behind a premise that Ukraine itself must determine the conditions for peace, Denmark seeks with its actions and words to leave Ukraine with no other choice but to continue the military confrontation with Russia," he said.
Kyiv said the jet was vital to the success of its bid to drive Russian forces from its territory in a counteroffensive that has proceeded slowly since its launch in early June, as it would prevent Russian fighter jets attacking advancing forces.
"Superiority in the air is key to success on the ground," air force spokesman Yuriy Ihnat was quoted as saying by Ukrainian media.
Danish Defence Minister Jakob Ellemann-Jensen said Ukraine may only use the donated F-16s within its own territory.
"We donate weapons under the condition that they are used to drive the enemy out of the territory of Ukraine. And no further than that," Ellemann-Jensen said on Monday.
"Those are the conditions, whether it's tanks, fighter planes or something else," he said.
Denmark will deliver 19 jets in total. The Netherlands has 42 F-16s available in all but has yet to decide whether all of them will be donated.
Ukrainian President Volodymyr Zelensky has called the decision a "breakthrough agreement."
Defense Minister Oleksiy Reznikov said on Saturday that Ukrainian pilots had begun training, but it would take at least six months and possibly longer to also train engineers and mechanics.