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

Estonia, a NATO member, summoned the Russian ambassador on Tuesday in protest of an “extremely serious” violation of its airspace by a Russian helicopter, Reuters reported.

The Estonian military and foreign ministry said in a statement on Tuesday that a Russian border guard MI-8 helicopter had flown over a point in the country’s southeast without permission on June 18.

The helicopter was in Estonia’s airspace for almost two minutes, Estonia’s military said, adding that the helicopter had not presented a flight plan, had its transponder switched off, and failed to maintain radio contact with Estonian Air Navigation Services.

"Estonia considers this an extremely serious and regrettable incident that undoubtedly causes additional tensions and is completely unacceptable," the foreign ministry said in a statement. The alleged intrusion was the second violation of Estonia's airspace this year.
According to Estonian officials, Russian troops are also simulating daily missile strikes on Estonia.

"It's never been as serious as it is now. It's real life. They're actually mimicking missile strikes on NATO territory and letting us know they're doing it," Kusti Salm, the chief of staff of the Estonian Defense Ministry, said.

In its statement, the Estonian Foreign Ministry also repeated calls for Russian troops to leave Ukraine.

"Russia must stop threatening its neighbors and understand that the price of the aggression Russia launched against Ukraine is indeed high," it added.

Estonia did not forget to express solidarity with fellow Baltic and NATO nation Lithuania, which Moscow says will be punished for banning the transit of some goods to the Russian exclave of Kaliningrad.

The U.S. stated on Tuesday that NATO's obligations to Lithuania are "ironclad" in the face of Russia's threats. “We stand by our NATO allies and we stand by Lithuania,” State Department spokesman Ned Price said at a press conference.

“Specifically our commitment to NATO’s Article Five — the premise that an attack on one would constitute an attack on all — that commitment on the part of the United States is ironclad,” Price added.

Amid U.S. reassurances, President Joe Biden scored an 89% approval rating in Ukraine according to a local poll published on Monday. British Prime Minister Boris Johnson shares the highest approval rating in Ukraine with Polish President Andrzej Duda, with both polling at 90%.

German Chancellor Olaf Scholz recorded the lowest approval among major leaders with a 41% rating. Hungarian Prime Minister Viktor Orban, who refused to supply Ukraine with weapons and has been equivocal about his condemnation of Russian President Vladimir Putin in the wake of Russia's invasion of Ukraine, scored a negative rating in the poll.

The research also revealed a vast majority of Ukrainians (89%) supporting the idea of joining the European Union, with 69% believing that Ukraine could join the bloc in five years. A further 76% of Ukrainians said they back their country's NATO membership.

Alexander Drueke and Andy Huynh, two Americans feared to have been captured while fighting in Ukraine, are being held in a detention facility in eastern Ukraine’s Donetsk region, Russia's Interfax reported, citing an unnamed source.

The State Department said earlier that the Kremlin has not yet officially confirmed to the U.S. that the men have been captured, much less shared any information on their location.

State Department spokesperson Ned Price said Tuesday that the U.S. has reached out to Russia about the missing Americans, but received no answers.

"We are working hard to learn more about reports of Americans who may be in Russian custody, or in the custody of Russian proxy forces. We have been in touch with Russian authorities regarding U.S. citizens who may have been captured while fighting in Ukraine," Price said.

Senior State Department officials said Tuesday that the U.S. has not received any direct information from Russian authorities or any of their proxy forces about Alexander Drueke and Andy Huynh, two American citizens feared to have been captured while fighting in Ukraine.

While the Kremlin's spokesman has publicly labeled Drueke and Huynh as mercenaries and said "they should be held responsible," Moscow has not yet officially confirmed to the U.S. that the men have been captured.

But senior State Department officials reiterated that the U.S. has been in contact with the Russian government to remind them of the protections granted to prisoners of war under the Geneva Conventions, even though the Kremlin argues that as "soldiers of fortune" the detainees would not be covered by those protections and could face the death penalty.

"We obviously disagree vigorously. And we have made our position clear to the Russian government," one official said.

The Geneva Conventions outline the humanitarian rights given to prisoners of war, however, mercenaries are not given the same protections.

When asked if the Americans could face the death penalty, Kremlin spokesman Dimitry Peskov said this week, "Yes, we do not rule out anything."

White House spokesman John Kirby on Tuesday called that "appalling."

"It's appalling that a public official in Russia would even suggest the death penalty for two American citizens that were in Ukraine," he said.

Kirby added that the U.S. was still "trying to learn more about these two individuals."

-ABC News' Shannon Crawford and Ben Gittleson

Russia now controls about 96% of the Luhansk region in eastern Ukraine.

Ukrainian forces are fighting to hold onto several municipalities in the Luhansk region: Severodonetsk, Lysychansk and the three neighboring villages of Pidlisne, Myrna Dolyna and Toshkivka.

Serhiy Haidi, the head of the Luhansk Regional State Administration, said Ukrainian forces are still holding on to the city of Lysychansk because it sits on elevated ground, giving them a tactical advantage. Russian forces have been heavily shelling the city where approximately 10,000 civilians remain. More than 10 high-rise buildings, private homes and a police station have been destroyed.

In Severodonetsk, Russian forces continue to fire on the Azot chemical plant where 568 civilians are sheltering.

-ABC News' Fidel Pavlenko, Natalya Kushnir and Christine Theodorou