KYIV, Ukraine (NewsNation) — Ukrainian President Volodymr Zelenskyy called on U.S. President Joe Biden and other world leaders for more support as they met for talks focused on pressuring Russia to end the invasion that is entering its second month.

“It feels like we’re in a gray area, between the West and Russia, defending our common values,” Zelenskyy said in his video address at Thursday’s emergency NATO summit. “This is the scariest thing during a war — not to have clear answers to requests for help.”

Zelenskyy is asking that NATO provide “effective and unrestricted” support to Ukraine, including any weapons the country needs.

This comes as G-7 nations announced they are restricting the Russian central bank’s use of gold in transactions while the U.S. announced a new round of sanctions targeting more than 400 elites and members of the Russian State Duma.

“The U.S. Department of the Treasury’s Office of Foreign Assets Control (OFAC) is designating key enablers of the invasion. This includes dozens of Russian defense companies, 328 members of the Russian State Duma, and the head of Russia’s largest financial institution,” the department said in a statement.

The Russian State Duma, the lower house of the Federal Assembly of Russia, “continues to support Putin’s invasion, stifle the free flow of information, and infringe on the basic rights of the citizens of Russia. We call on those closest to Putin to cease and condemn this cold-blooded war,” added Secretary of the Treasury Janet L. Yellen.

Biden tweeted that Russian elites should “share the pain” of these sanctions.

And it appears that the pressure has been working, causing the Soviet state to crumble from within.

“We have seen credible evidence that all is not well in Russia’s domestic security service,” Michael Weiss, a Russian expert at New Lines magazine, said Thursday evening on “The Donlon Report.” “There are cracks in this regime.”

During the NATO summit in Brussels, Biden said the alliance was more united than ever, and that Putin will alter course.

“Increasing the pain and the demonstration is why I asked for this NATO meeting today,” Biden said. “To be sure that after a month we will sustain what we are doing, not just next month, the following month but for the remainder of this entire year. That is what will stop him.”

The U.S. president also said he wants Russia out of the G-20, although he added that if other nations disagree, Ukraine leaders should be allowed in for conversations.

U.S. officials said Thursday that the United States will welcome up to 100,000 refugees from Ukraine as 3.5 million flee Russia’s invasion. Biden announced more than $1 billion in humanitarian assistance.

Russia unleashed its invasion Feb. 24, but instead of swiftly toppling Ukraine’s government, its forces are bogged down in a grinding military campaign and its economy is laboring under punishing international sanctions.

Ukraine and Russia exchanged a total of 50 military and civilian prisoners Thursday, Ukrainian deputy prime minister Iryna Vereshchuk said. Reports of others local prisoner changes on a smaller scale have also surface, including nine Russian soldiers for a captured Ukrainian mayor. 

The Russian stock market resumed limited trading Thursday under heavy restrictions almost one month after prices plunged and the market was shut down following the invasion. Trading of a limited number of stocks, including energy giants Gazprom and Rosneft, took place under curbs that are meant to prevent a repeat of the massive selloff that took place on Feb. 24 in anticipation of Western economic sanctions. Foreigners cannot sell and traders are barred from short selling, or betting prices will fall. The benchmark MOEX index gained 8% in the first minutes of trading.

Ukraine’s navy reported Thursday that it had sunk the Russian ship Orsk in the Sea of Asov near the port city of Berdyansk. It released photos and video of fire and thick smoke coming from the port area. Russia did not immediately comment on the claim.

Military experts said the battle for the Black Sea is especially important for Ukraine and suggested that attacks on Russian ships could increase in the coming days.

“I think we’re going to see an escalation on the Ukrainian’s part going after some of these ships in the Black Sea because they make great targets, they’re close to shore…and it’s an opportunity for the Ukrainians to impose some costs on Russia,” Bryan Clark, a senior fellow and director at the Hudson Institute, said on “NewsNation Prime” Thursday.

Russia has been in possession of the port since Feb. 27, and the Orsk had debarked armored vehicles there on Monday for use in Moscow’s offensive, the Zvezda TV channel of the Russian Defense Ministry said earlier this week. According to the report, the Orsk was the first Russian warship to enter Berdyansk, which is about 50 miles west along the coast from the besieged city of Mariupol.

Meanwhile, the Russian military said it will offer safe passage to foreign ships that have been stranded in Ukrainian ports.

The safe route will be open daily from 8 a.m. to 7 p.m. Moscow time starting Friday, Col. Gen. Mikhail Mizintsev said.

With its ground forces slowed or stopped by hit-and-run Ukrainian units armed with Western-supplied weapons, Russian President Vladimir Putin’s troops are bombarding targets from afar, falling back on the tactics they used in reducing cities to rubble in Syria and Chechnya.

NATO estimates that between 7,000 and 15,000 Russian troops have been killed since the start of the invasion. Ukraine officials say thousands of civilians and troops have died.

Ukraine also claims to have killed six Russian generals. Russia acknowledges just one dead general.

Still, fighting continues. Russian official Dmitry Rogozin said the country’s nuclear arsenal would help deter the West from intervening in Ukraine.

“The Russian Federation is capable of physically destroying any aggressor or any aggressor group within minutes at any distance,” said Rogozin, who heads the state aerospace corporation, Roscosmos, and oversees missile-building facilities. He noted in his televised remarks that Moscow’s nuclear stockpiles include tactical nuclear weapons, designed for use on battlefields, along with far more powerful nuclear-tipped intercontinental ballistic missiles.

Ukraine says more than 400,000 of its citizens have been forcibly taken to Russia. Ukrainian Ombudsman Lyudmyla Denisova said at a briefing Thursday that the Ukrainians, including 84,000 children, were taken by Russian troops from Mariupol and other besieged Ukrainian cities

The Ukrainian Foreign Ministry said Thursday Russia is making arrangements to forcibly relocate up to 6,000 civilians to Russia from the besieged port of Mariupol to “Russian filtration camps in order to use them as hostages and put more political pressure on Ukraine.”

The Foreign Ministry also accused Russian troops of obstructing attempts to evacuate civilians from Mariupol, including by seizing bus drivers sent to collect civilians. U.S. officials long have warned that Russia’s military doctrine envisages an “escalate to de-escalate” option of using battlefield nuclear weapons to force the enemy to back down in a situation when Russian forces face imminent defeat. Moscow has denied having such plans.

Rogozin did not make clear what actions by the West would be seen as meddling, but his comments almost certainly reflect thinking inside the Kremlin. Putin has warned the West that an attempt to introduce a no-fly zone over Ukraine would draw it into a conflict with Russia. Western nations have said they would not create a no-fly zone to protect Ukraine.

A new NewsNation poll shows 52% of Americans approve of a no-fly zone over Ukraine. However, many think the price Russia has paid for its invasion is “too weak.”

The encircled port city of Mariupol has seen the worst devastation of the war, enduring weeks of bombardment and now street-by-street fighting.

In their last update, over a week ago, Mariupol officials said at least 2,300 people had died, but the true toll is probably much higher. Airstrikes in the past week destroyed a theater and an art school where civilians were sheltering.

Zelenskyy said 100,000 civilians remain in the city, which had a population of 430,000 before the war. Efforts to get desperately needed food and other supplies to those trapped have often failed.

In the besieged northern city of Chernihiv, Russian forces bombed and destroyed a bridge that was used for aid deliveries and civilian evacuations, regional governor Viacheslav Chaus said. Another government official said a  “catastrophe” is unfolding for the population as Russian troops deliberately target food stores in a near-monthlong siege.