The Polish envoy to Kyiv said on Thursday that imposing a no-fly zone over Ukraine would help bring the war to a speedier end and save lives, as Russia continued to strike multiple cities.

President Volodymyr Zelenskiy of Ukraine has been begging with NATO to enforce a no-fly zone, but the alliance is leery of taking any action that may put it in direct conflict with Russia.

“Every day of delay costs hundreds of lives,” Bartosz Cichocki, a journalist from Kyiv, told private channel TVN24. “This is an extension of the issue that might be resolved much more quickly and precisely if the airspace were closed.”

The US turned down an unexpected request from Poland to move its Russian-made MiG-29 fighter planes to a US facility in Germany and put them at the disposal of the US as a method to bolster Ukraine’s air force.

On Wednesday, Poland’s prime minister stated that any delivery of fighter planes to Ukraine must be coordinated by NATO nations.