LISBON, Portugal (AP) — Ukrainian President Volodymyr Zelenskyy received a second $1 billion promise of military aid in as many days Tuesday during a whirlwind tour of three European Union countries, while President Vladimir Putin warned that hitting Russian soil with Western-supplied weapons could set the war on a dangerous new path.

The aid pledge for 2024 came from Belgium, which topped up the money with a commitment to give Ukraine 30 F-16 fighter jets in the next four years.

“Our task is to use the first F-16 on the battlefield this year and in such way fortify our positions,” Zelenskyy said.

He later traveled to Portugal, where he said it was important that Ukraine’s supporters don’t allow themselves to be misled by Russia and that “we don’t grow tired of the war.”

The onslaught by the Kremlin’s better-equipped forces that is unfolding in eastern and northeastern Ukraine as summer approaches has brought Ukraine its biggest military test since Russia’s full-scale invasion began in February 2022.