WASHINGTON (NewsNation Now) — The United Nations Security Council will convene an emergency meeting Wednesday night after Ukraine requested help ahead of a possible Russian invasion.

The meeting is scheduled for 9:30 p.m. ET.

Earlier, Ukraine’s president said Russian President Vladimir Putin is dodging his calls and implored the Kremlin to stand down.

In an emotional address to the nation late Wednesday, Ukrainian President Volodymyr Zelenskyy rejected Moscow’s claims that his country poses a threat to Russia and lamented that a Russian invasion would cost tens of thousands of lives.

“The people of Ukraine and the government of Ukraine want peace,” he said in Russian, hours after declaring a nationwide state of emergency. But if the nation comes under an attack, “we will fight back.”

The Kremlin on Wednesday said that the rebel leaders in eastern Ukraine have asked Russia for military assistance to fend off the Ukrainian “aggression.”

The appeal raises the prospect of Russia’s direct military involvement in eastern Ukraine amid Western fears that Moscow is poised to launch an all-out invasion of its neighbor.

Kremlin spokesman Dmitry Peskov said the rebel chiefs wrote to Putin to tell him that shelling by the Ukrainian military has caused civilian deaths and forced many people to flee.

Putin said Wednesday that he was open to searching for “diplomatic solutions” with the West after President Joe Biden imposed new, strict sanctions on Russia, calling the crisis “the beginning of an invasion.”

At the same time, the Ukrainian National Security and Defense Council Wednesday imposed a state of emergency on the entire country, except Donetsk and Luhansk regions, where Operation Joint Forces is underway. Officials said additional security measures could include increased police presence at public facilities, traffic restrictions and additional transport and document checks.

“I would tell you that we assess that the Russian military forces arrayed around Ukraine and Belarus are as ready as they can be,” a senior Ukraine official told NewsNation. “We would assess that about 80% of their forces are in what we would consider forward positions, ready to go.”

Ukraine’s Minister for Digital Transformation Mykhailo Fedorov said a wave of denial-of-service attacks targeted official websites and some banks Wednesday, driving the sites of the Parliament, Cabinet and Foreign Ministry offline and causing interruptions or delays to the sites of the Defense Ministry and Interior Ministry, which controls the police.

Also Wednesday, Russia began evacuating its embassy in Kyiv, and Ukraine urged its citizens to leave Russia as the region braced for further confrontation. 

“Our country stays open for direct and honest dialogue, for the search of diplomatic solutions for the most complex issues,” Putin said in a televised address. “But I will repeat: Russia’s interests, our citizen’s safety are absolute. So we will continue strengthening and developing our army and navy, increasing their efficiency, providing them with the most advanced equipment.”

However, Biden said in remarks Tuesday, “None of us will be fooled” by Putin’s claims about Ukraine. He warned that more sanctions could be on the way if Putin proceeds further.

Overnight, satellite images captured Russia deploying more military vehicles, troop tents and supplies including blood into Belarus near the Ukrainian border.

The new sanctions include blocking two Russian financial institutions, the VEB and military bank, and cutting Russia’s government off from Western financing.

“They can no longer raise money from the West and cannot trade in its new debt on our markets, or European markets either,” Biden said.

Biden announced Tuesday that he is moving U.S. forces to the Baltic states, and positioning Apache attack helicopters and F-35 fighter jets to parts of Eastern Europe, to protect NATO allies.

The country joined 27 European Union members who unanimously agreed Tuesday to levy their own initial set of sanctions targeting Russian officials over their actions in Ukraine.

Biden on Wednesday directed his administration to impose sanctions on Nord Stream 2 AG and its corporate officers, one day after Germany took steps to halt the process of certifying the multibillion-dollar gas pipeline from Russia.

“These steps are another piece of our initial tranche of sanctions in response to Russia’s actions in Ukraine,” Biden said in a statement. “As I have made clear, we will not hesitate to take further steps if Russia continues to escalate.”

Now, Ukraine is issuing sanctions on Russian lawmakers who supported the independence of the Donetsk and Luhansk regions.

The country’s foreign minister, Dmytro Kuleba, said Wednesday on Twitter: “To stop Putin from further aggression, we call on partners to impose more sanctions on Russia now.”

For now, it seems, the door is closing on diplomacy after Biden canceled any plans for a meeting with Putin and Secretary of State Antony Blinken called off his meeting with the Russian foreign minister.

The Kremlin has warned that Americans will face financial consequences for sanctions against Russia.

The Biden administration has vowed to closely monitor energy supplies for any disruptions, and execute a plan in coordination with major oil producers to secure stability and global energy supplies.

The Associated Press contributed to this report.