"We see in Ukraine how Russia delivers terror from above, so we will strengthen the shield that protects our skies," the NATO secretary general Rutte was to say in a speech to the Chatham House think-tank in London, according to comments released in a statement.

To maintain credible deterrence and defence, NATO needs "a 400-percent increase in air and missile defence".

"The fact is, we need a quantum leap in our collective defence," he was to say.

Rutte will meet UK Prime Minister Keir Starmer on Monday ahead of his speech, their second Downing Street talks since Starmer came into power in July 2024.

His comments come ahead of a NATO summit in the Netherlands this month.

US President Donald Trump is pressurising alliance members to announce a major boost in their military budgets.

He is pushing NATO members to increase their defence spending to five percent of their gross domestic product (GDP), up from the current target of two percent.

US Secretary of Defense Pete Hegseth said last week in Brussels the allies were close to an agreement on the five-percent target, which could be formalised at the summit in The Hague.

NATO members have been scrambling to bolster their defence capabilities since Russia launched its war against Ukraine in February 2022.

"Danger will not disappear even when the war in Ukraine ends," Rutte was to say.

"We must have more forces and capabilities to implement our defence plans in full."

"Our militaries also need thousands more armoured vehicles and tanks, millions more artillery shells."

Britain announced plans last week to build up to 12 nuclear-powered attack submarines and six munitions factories to rearm the country in response to what it said were threats from Russia.

Earlier this year, Starmer's government pledged to increase defence spending to 2.5 percent of GDP by 2027, but has not yet set a firm timeline for further hikes.

"NATO has to become a stronger, fairer and more lethal alliance," Rutte will add.