NATO Secretary General Jens Stoltenberg said the defense alliance are committed to "providing heavy weapons and long-range systems for Ukraine to prevail."

He made the remarks on Wednesday ahead of a NATO defense ministers meeting that will take place on Wednesday and Thursday at the organization's headquarters in Brussels.

As for Sweden and Finland's applications to join NATO, the chief said the applications are "historic", and security concerns of all NATO allies will be taken into account. 

Stoltenberg said Ukrainian President Volodymyr Zelenskyy is invited to NATO summit in Madrid later this month, and is looking forward to his address.