Dutch Prime Minister Mark Rutte pledged to send F-16 fighter jets to Kyiv during a surprise visit by Ukrainian President Volodymyr Zelenskiyto the Netherlands.

Speaking at a joint news conference with the Ukrainian leader on Sunday, Rutte said the jets will be sent once pilots are trained for the aircraft.

The announcement comes on the heels of US approval to Denmark and the Netherlands to send their F-16s to Ukraine when the instruction concludes. The two NATO allies said Friday they received a letter from US Secretary of State Antony Blinken giving the green light for deliveries.

Zelenskiy visited Sweden Saturday to start a new round of talks with allies on weapons systems that could strengthen the country’s defenses and boost a slow-moving offensive to take back land occupied by Russia.

The Netherlands currently has 42 F-16 fighter jets in its inventory, 24 of which are being used and can’t be sent to Ukraine until mid-2024. The Netherlands and Denmark have been leading the coalition to train the Ukrainian pilots.

Danish officials haven’t yet said when they might send the aircraft. The Nordic country has previously said it wants to hold on to its roughly 30 F-16 jets through 2024. The aircraft are being phased out as Denmark receives 27 new F-35 Joint Striker Fighters it has ordered from Lockheed Martin Corp.

Rutte, who announced his decision to quit politics as the longest-serving premier of the Netherlands last month, vowed the abrupt collapse of his government will not change The Hague’s stance on Ukraine and the caretaker cabinet will continue to support Kyiv in its military response to Russia’s invasion.