Asked on June 2 about Ukraine's aspirations to join NATO, Kremlin spokesman Dmitry Peskov said it "would be a potential problem for many, many years."
Hanging over the deliberations is the question of whether alliance members can show unity by forging agreements ahead of the July 11-12 summit in the Lithuanian capital.
But all agree on the need to further boost Ukraine's security between now and the day it joins NATO.
Gabrielle Tarini, co-author of a new RAND Corporation report on Ukraine reconstruction, said that until Ukraine can join NATO the alliance needs to explore such measures.
NATO will bolster a program of non-lethal aid for Ukraine's security forces to help them transition from Soviet-era to NATO standards, he said.
Persons:
Volodymyr Zelenskiy, NATO Julianne Smith, Smith, Dmitry Peskov, Vladimir Putin, Ukraine's, Putin, Jens Stoltenberg, Stoltenberg, Emmanuel Macron, Gabrielle Tarini, Jonathan Landay, Andrew Gray, Humeyra Pamuk, Andrea Shalal, John Irish, Don Durfee, Grant McCool
Organizations:
NATO, Russian, Atlantic Treaty Organization, Kyiv, Kremlin, Ukraine, U.S . National Security, Diplomats, RAND Corporation, Ukraine Council, Thomson
Locations:
Ukraine, Vilnius, U.S, Germany, Russia, Europe, Lithuanian, Eastern, Poland, United States, Israel, Russian, Kyiv, Washington, Paris