Nato defence ministers will gather in Brussels on Tuesday and Wednesday to coordinate weapons supplies for Ukraine and discuss the threat posed by spy balloons.
The meeting at the alliance's headquarters in the Belgian capital comes ahead of the first anniversary of Russia's full-scale invasion of Ukraine.
It also follows the shooting down of a series of objects in western airspace by the US military, including a suspected Chinese spy balloon.
Defence Secretary Ben Wallace, who is expected to join the Brussels meeting on Wednesday, has announced Britain will conduct a security review into the issue.
Ahead of the meeting, Nato secretary-general Jens Stoltenberg said defence ministers would work to strengthen the alliance's deterrence and defence, increase industrial capacity and replenish members' munitions stockpiles, as well as "step up and sustain our support for Ukraine".
"It is clear that we are in a race of logistics," he told a press conference on Monday.
"Key capabilities like ammunition, fuel and spare parts must reach Ukraine before Russia can seize the initiative on the battlefield.
"Speed will save lives."
The Nato chief warned that "we're seeing the start already" of a fresh Russian offensive in Ukraine.
He also said he expected the possible supply of fighter jets to Kyiv to be discussed at the two-day gathering.
Ukrainian President Volodymyr Zelensky last week continued his push for combat aircraft and long-range missiles as he toured European capitals.
The UK will be the first nation to start training Ukrainian pilots on Nato-standard aircraft, and Mr Wallace will investigate which planes the UK could potentially give to Ukraine.
In the wake of the alleged spy balloon incident, allies will also discuss strengthening the defence of their airspace and boosting cooperation in space, Mr Stoltenberg said.
Western leaders will gather for the Munich Security Conference this weekend.