He told reporters on Thursday on the Italian island of Capri, where a meeting of G7 foreign ministers is taking place, Ukrinform reports citing Reuters.
"We have compiled data about the different air defence systems we have in NATO and focused on the Patriot systems. And we are working with allies to ensure that they redeploy some of their systems to Ukraine," he told reporters on the sidelines of a meeting of G7 foreign ministers in Italy.
"We are working at the possibility of more Patriot batteries to Ukraine. We are in dialogue with some specific countries," Stoltenberg said, calling supply of the Patriot "critical" as it is the most advanced defence system the alliance can count on.
Stoltenberg said other defence systems might also be provided to Ukraine, including the NASALS surface-to-air missile system.
"Delays in the delivery of air defence mean that more Russian missiles will hit their targets in Ukraine. Delays in delivery of ammunition mean that Russia will be able to push more along the front line," he added.
"I am encouraged by the commitment and the determination by NATO allies to stand up for Ukraine," he told reporters, adding there were encouraging signs that the U.S. Congress might soon unlock an aid package for Ukraine worth $60.84 billion.
As reported, Germany has called on the European Union and NATO to strengthen Ukraine's air defense as soon as possible. German Defense Minister Boris Pistorius and Foreign Minister Annalena Baerbock launched a joint initiative and called on third countries to review their capabilities. The initiative is being discussed this week at a meeting of G7 foreign ministers.
On Thursday, Dutch Prime Minister Mark Rutte offered to buy Patriot air defense systems from countries that have them but do not want to provide them to Ukraine.