• The U.S. Ambassador to the U.N. has said the U.S. has "credible information" that Russia has compiled lists of Ukrainians "to be killed or sent to camps" following an invasion.
• Western officials have said that Russia may use false claims about the ongoing conflict in eastern Ukraine as a pretext for an invasion.
• Russian President Vladimir Putin said on Monday that Moscow should consider formally recognizing the self-proclaimed republics in eastern Ukraine as independent.

Russia has compiled lists of Ukrainians to target after an invasion, a U.S. official has said, as President Vladimir Putin is set to address his country's security council.

In a letter to the U.N.'s Human Rights chief, seen by NBC News, U.S. Ambassador to the U.N. Bathsheba Nell Crocker said the U.S. had "credible information" that Russia has compiled lists of Ukrainians "to be killed or sent to camps" following an invasion. The contents of the letter were first reported Sunday evening by The Washington Post.

"We also have credible information that Russian forces will likely use lethal measures to disperse peaceful protests or otherwise counter peaceful exercises of perceived resistance from civilian populations," she said.

The Kremlin refuted Crocker's accusations on Monday, dubbing reports that Russia had drawn up such lists as "fiction" when asked about it by reporters.

"You do understand that this is an absolute fake, that it's a lie?" he said.

Crocker also said in her letter that other human rights violations and abuses in the aftermath of an invasion were being planned in Moscow. Those who oppose Russian actions — including Russian and Belarusian dissidents in exile in Ukraine — as well as journalists, religious and ethnic minorities and the LGBTQI+ community were at risk of being subjected to these abuses, Crocker warned.

Ukrainian Defense Minister Alexei Reznikov told Ukrainian broadcaster ICTV on Monday that an invasion was unlikely to occur "tomorrow or the day after tomorrow," as no Russian "strike groups" had congregated at the border.

He added, however, that these groups could be set up within weeks.

It came after the White House warned Moscow was planning to launch a full-scale attack on Ukraine "very soon," and British Prime Minister Boris Johnson warned there was evidence Russia is planning "the biggest war in Europe since 1945."

Last week, the U.S. estimated there were now between 169,000 and 190,000 Russian troops in and near Ukraine, up from 100,000 at the end of January. The updated figures came despite Russian claims that it had begun to withdraw troops from the border, which were also contradicted by NATO and the EU.

Russia has repeatedly denied it plans to invade neighboring Ukraine. It has demanded guarantees that Ukraine never be allowed to join NATO — a request rejected by the military alliance and the U.S. — and has said it wants the organization to scale back its presence in eastern Europe.

In a special meeting on Monday of Russia's security council, Putin claimed threats to Russia would increase substantially if Ukraine joins NATO, according to Reuters.

Putin to consider recognition of breakaway regions

The meeting of the council, led by Putin, came as fighting between Ukrainian authorities and pro-Russian separatists in eastern Ukraine, which has been ongoing for eight years, continued to escalate.

Over the past week, Russian state media and Ukrainian authorities have pointed the finger at one another repeatedly for carrying out shelling attacks and other ceasefire violations.

Last week, the leader of one of the separatist-held areas in eastern Ukraine announced that residents would be evacuated to Russia with the assistance of the Russian government. It came after the country's lawmakers asked Putin last week to officially recognize two self-declared republics in Ukraine's east as independent.

Russian state media reported on Monday that Eduard Basurin, official representative of one of those breakaway areas, the Donetsk People's Republic, said in a YouTube video that self-proclaimed republics in eastern Ukraine needed financial, military and moral assistance from Russia.

The leaders of two Ukrainian areas held by pro-Moscow separatists also urged Russia to officially recognize them as independent on Monday.

Putin told his security council that recognition of the breakaway regions needed to be considered, Reuters reported.

Dmitry Kozak, Putin's special representative on Ukraine, said on Monday that Russia had been forced to spend "astronomical sums" on humanitarian aid for the two breakaway regions.

Fighting in eastern Ukraine escalates

On Monday, the Ukrainian Defense Ministry said Russian occupation forces had carried out "yet another provocation with the aim of falsely accusing Ukrainian service members."

"[The] aggressor opened heavy armament fire from the settlement of Lobacheve targeting Luhansk," the ministry said in a statement.

Over the past day, Ukrainian authorities said they had recorded 80 ceasefire violations, 72 of which involved the use of weapons prohibited by the Minsk agreements, treaties signed in 2014 and 2015 by Ukraine, Russia and separatist leaders.

"With Ukrainian defenders refraining from any aggressive acts that could possibly trigger a violent response, the occupation forces continue to destroy civilian infrastructure on the temporarily occupied territories and sporadically shell civilian settlements," Ukraine's Ministry of Defense added. "It is obvious that the adversary continues to use the Russian propaganda machine to wage information warfare, to falsely accuse the Armed Forces of Ukraine and to further escalate the situation."

On Saturday, the Organization for Security and Co-operation in Europe recorded more than 1,500 ceasefire violations in eastern Ukraine, including 1,413 explosions.

The east of Ukraine, near the Russian border, has long been the scene of low-level fighting. The OSCE has regularly reports violations of the cease-fire in eastern Ukraine during the eight-year conflict, in which around 13,000 people have died, but the numbers have risen drastically in recent days.

Ukraine says Russia spreading fake news

Russian state media claimed on Monday that the Russian military and border guards had killed five people when a "group of saboteurs from the territory of Ukraine" attempted to cross the border into Russia.

The alleged incident was said to have occurred at around 6 a.m. local time near the village of Mityakinskaya in the Rostov region.

Ukraine's Kuleba denied Russia's allegations on Monday, saying on Twitter that Ukraine had not carried out any attacks and had no intention of doing so.

"Russia, stop your fake-producing factory now," he said.

Western officials have warned that Russia could make false claims about the conflict in Ukraine's east to justify military aggression and an invasion, in what has been dubbed a "false flag attack" by the U.S. and the U.K.

U.S. Secretary of State Antony Blinken told the U.N. Security Council last week that this could include a fabricated terrorist bombing, the invented discovery of a mass grave, a staged drone strike against civilians or a fake chemical weapon attack.

U.K. Prime Minister Boris Johnson's spokesperson told reporters on Monday that "elements of the Russian playbook" were "starting to play out in real time."

Ukrainian Foreign Minister Dmytro Kuleba is meeting with EU foreign ministers in Brussels on Monday.

Biden agrees 'in principle' to meet Putin

On Sunday, the White House announced that President Joe Biden has agreed "in principle" to a meeting with Russian leader Vladimir Putin, provided there is no invasion of Ukraine. However, the U.S. still warned that Moscow is preparing for "a full-scale assault on Ukraine very soon."

The Kremlin said on Monday that there were currently no concrete plans for a meeting between Putin and Biden, according to Reuters.

Blinken is scheduled to meet with Russian Foreign Minister Sergey Lavrov in Europe later this week, again provided Moscow does not initiate any military action.

Biden on Sunday convened a meeting of the U.S. National Security Council to discuss the escalating tensions around Ukraine.