"To invite a new ally we need consensus and all allies agree that Ukraine will become a member, but it is too early to say exactly when that will happen," Stoltenberg said ahead of the NATO Summit in Washington.
In April, NATO Secretary-General Jens Stoltenberg during a visit to Kiev said Ukraine has a rightful place in NATO and that the alliance is working on placing it on an irreversible path toward membership in NATO when the time may be right.
Russia has repeatedly said it stands against Ukraine's membership in NATO due to national security concerns, but never opposed Kiev's aspirations to join the European Union.