Russia-Ukraine updates: Russian missiles hit close to nuclear reactors: IAEA director

The Russian military committed "a clear war crime" when its forces bombed a packed drama theater in the Ukrainian city of Mariupol in March, Amnesty International said Thursday.

The London-based international human rights group published a new report documenting how the deadly blitz on the Donetsk Academic Regional Drama Theater unfolded, citing interviews with numerous survivors and witnesses as well as "extensive digital evidence," which included photographs, videos, radio intercepts, satellite imagery and radar data. The report concluded that the evidence indicates the attack "was almost certainly an airstrike carried out by the Russian military," with the theater as "the intended target."

"After months of rigorous investigation, analysis of satellite imagery and interviews with dozens of witnesses, we concluded that the strike was a clear war crime committed by Russian forces," Amnesty International Secretary-General Agnes Callamard said in a statement Thursday.

Russian President Vladimir Putin still wants to seize most of Ukraine, and the outlook for the war remains grim, Avril Haines, the top U.S. intelligence officer, said Wednesday as reported by Reuters.

“In short, the picture remains pretty grim and Russia's attitude toward the West is hardening," Haines said at a Commerce Department conference.

The intelligence officer added that U.S. spy agencies expect the war to grind on “for an extended period of time.” But the Russian forces are so degraded by combat, Haines said, that they likely can only achieve incremental gains in the near term.

Haines also said it will take years for Russia to rebuild its forces. Still, U.S. intelligence agencies foresee three possible scenarios in the war, according to Haines, the most likely being a grinding conflict in which Russian forces "make incremental gains, with no breakthrough."

The other scenarios include a major Russian breakthrough and Ukraine succeeding in stabilizing the frontlines while achieving small gains, perhaps near the Russian-held city of Kherson and other areas of southern Ukraine.

Ukraine is likely to rely on more NATO support as the conflict drags on, with Ihor Zhovkva, the Deputy Head of the Ukrainian Presidential Office, stating Wednesday that Ukraine believes it already meets NATO standards and maintains a course to continue integration.

"No one removes Ukraine's Euro-Atlantic integration from the agenda," Zhovkva said at the NATO summit in Madrid.

Zhovka, who headed the Ukrainian delegation in Madrid, said he was satisfied with the results of the summit. The official also stressed that Ukraine maintains its course to join NATO.

Russia warned Tuesday that Ukraine joining NATO could lead to World War III should Kyiv then attempt to encroach on the Moscow-annexed Crimean Peninsula.

-ABC News' Edward Szekeres, Max Uzol, Natalya Kushnir and Yuriy Zaliznyak

Ukrainian President Volodymyr Zelenskyy addressed the NATO summit Wednesday, commending the decision to invite Finland and Sweden to join NATO.

Zelenskyy told the NATO leaders, "The goals of Ukraine are exactly the same as yours: We are interested in security and stability on the European continent and in the world."

“This is not a war of Russia only against Ukraine, this is a war for the right to dictate conditions in Europe,” he said.

-ABC News' Christine Theodorou

President Joe Biden met with Turkish President Recep Tayyip Erdoğan at the NATO summit in Madrid Wednesday, where he thanked Erdoğan for dropping his objections to Finland and Sweden becoming NATO members.

“I want to particularly thank you for what you did putting together the situation with regard to Finland and Sweden and all the incredible work you're doing to try to get the grain out of Ukraine and Russia,” Biden said.

“We think your pioneering in this regard is going to be crucial in terms of strengthening NATO for the future,” Erdoğan said. “And it's going to have a very positive contribution to the process between Ukraine and Russia.”

Senior administration officials told reporters Wednesday that the U.S. made no formal offer in exchange for Erdoğan dropping Turkey’s resistance to Finland and Sweden becoming NATO members.

The U.S. Department of Defense earlier came out in support of Turkey’s plans to modernize its aircraft fleet with American-made F-16s.

-ABC News' Gabe Ferris