Poland is considering a proposal from Kyiv to shoot down Russian missiles heading towards Polish territory while they are still in Ukrainian airspace.
The proposal was included in a security cooperation agreement signed by Volodymyr Zelenskyy and Polish Prime Minister Donald Tusk in Warsaw this week.
Ukraine's president said he was "confident" the arrangement could be implemented swiftly, though Poland will consult its NATO allies before attempting to shoot down any Russian missiles.
"At this stage, this is an idea. What our agreement said is we will explore this idea," Poland's foreign minister Radoslaw Sikorski told the American Enterprise Institute in Washington today.
Mr Sikorski confirmed that Russian missiles fired from the St Petersburg area towards Ukrainian targets had previously entered Polish airspace for about 40 seconds before turning towards their targets.