Ukraine’s newly arrived F-16 fighter jets were put on display Sunday by President Volodymyr Zelensky, who said the planes will boost the country’s war effort against Russia.

“These jets are in our sky and today you see them,” said Zelensky, standing in front of two of the fighter jets as two others flew overhead in close formation. “It’s good that they are here and that we can put them to use.”

Ukraine is also trying to get neighboring countries to help defend it against Russian missiles, Zelensky said.