Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

In a virtual address to members of Congress Wednesday, Ukrainian President Volodymyr Zelenskyy asked the U.S. to back a no-fly zone over the war-torn country.

If a no-fly zone is not possible, Zelenskyy asked for aircraft "to help Ukraine."

"Russia has turned the Ukrainian sky into a source of death for thousands" -- a "terror" Europe hasn't seen in 80 years, Zelenskyy said.

In an emotional appeal, Zelenskyy asked members of Congress to put themselves in the shoes of Ukrainians by remembering Pearl Harbor and the Sept. 11 attacks.

Zelenskyy expressed his gratitude for U.S. involvement, but called on Congress to do more.

"New packages of sanctions are needed constantly … we propose that the United States sanction all politicians in the Russian Federation who remain in their offices and do not cut ties with those who are responsible for the aggression against Ukraine," he said.

"Members of Congress, please take the lead. If you have companies in your districts who finance the Russian military machine... you should put pressure," he said.

"The destiny of our country is being decided," he said. "Russia has attacked not just us… it went on a brutal offensive against our values, basic human values."

Zelenskyy received a standing ovation before and after his remarks.

But White House press secretary Jen Psaki said Tuesday that a no-fly zone "is escalatory and could prompt a war with Russia."

"Providing the planes, our military did an assessment that’s based not just on the risk but whether it would have a huge benefit to them," Psaki said. "They assessed it would not because they have their own squadron of planes and because the type of military assistance that is working to fight this war effectively is the type of assistance we're already providing."

Fox News correspondent Benjamin Hall, who was reporting in Ukraine when he was injured by incoming fire that killed two colleagues, is now safe and out of the country, according to the network.

Hall "is alert and said to be in good spirits," Fox News anchor Bill Hemmer reported Wednesday.

Fox News cameraman Pierre Zakrzewski, 55, was newsgathering with Hall on Monday in Horenka, outside of Kyiv, when their vehicle was hit by incoming fire, the network said. Zakrzewski was killed while Hall was injured and hospitalized in unknown condition.

Ukrainian producer and fixer, 24-year-old Oleksandra Kuvshynova, who was working for Fox News during the war, was also killed in the shelling, according to the United Nations Educational, Scientific and Cultural Organization.

Russia’s lead negotiator in peace talks with Ukraine said on Wednesday Ukraine had proposed adopting a “neutral status,” along the lines of Austria or Sweden, that is a country that is not part of NATO but has its own military and close ties to the West, including European Union membership.

There has been no official confirmation from Ukraine, though President Volodymyr Zelenskyy has repeatedly said in recent days that Ukraine understands it will not be allowed to join NATO.

"The preservation and development of the neutral status of Ukraine, its demilitarization Ukraine -- a whole complex of questions connected with the size of the Ukrainian army,” Russia’s negotiator, Vladimir Medinsky, was quoted as saying by Russian media. “Ukraine proposes the Austrian, Swedish option of a neutral demilitarised state, but within that a state possessing its own army and navy. All these questions are being discussed at the level of the leaderships of the ministry of defense of Russia and Ukraine.”

Russia’s foreign minister Sergey Lavrov claimed on Wednesday that the negotiators in the fourth round of talks were discussing “concrete formulations” that are “close to agreement.”

An agreement that Ukraine wouldn’t seek to join NATO raises questions. Ukraine’s constitution includes a pledge to join the alliance that would likely need to be changed, which would be highly controversial.

If the Sweden-style status is acceptable to Russia that would also mean the Kremlin has significantly lowered its war aims. Ukraine was not close to joining NATO before the conflict and a commitment not to would be little more than affirming the status quo before Russia’s invasion.

"The goal pursued by Russia at these negotiations is exactly the same as the goal set by Russia at the very beginning of the special military operation," Medinsky said. "We need a peaceful, free and independent Ukraine, a neutral one, not a member of some military blocs or a member of NATO, but a country that would be our friend and neighbor, so that we could jointly develop relations and build our future and that would not serve as a bridgehead for a military and economic attack on our country. So, our goal is unchanged."

This is why "practically every digit or letter in the agreements" is being thoroughly discussed with the Ukrainian side, Medinsky said.

"We want this agreement to last for generations, so that our children live in peace, the foundation of which is laid by this negotiating process," he said.

Russia is also pursuing other demands in the talks, including the recognition of Crimea as part of Russia and the Russian-controlled separatist regions as independent. They also want changes in laws giving more guarantees for Russian-speakers in Ukraine.

-ABC News’ Patrick Reevell

Russia’s military forces are “struggling to overcome” Ukraine’s terrain as they attempt to push further into the country, the U.K. Ministry of Defence said on Wednesday.

“Russian forces have remained largely tied to Ukraine’s road network and have demonstrated a reluctance to conduct off-road manoeuvre,” the Ministry said in an update. “The destruction of bridges by Ukrainian forces has also played a key role in stalling Russia’s advance.”

Ukraine’s military has “adeptly exploited” Russia’s difficulty moving through the country, “frustrating the Russian advance and inflicting heavy losses on the invading forces,” the update said.

-ABC News’ Zoe Magee