Russia-Ukraine updates: US to ban Russian carriers from its airspace

As Ukraine calls on allies to impose harsher sanctions on Russia in response to Moscow’s recognition of the separatist regions in eastern Ukraine, several Western countries have announced some sanctions to start -- and warned more are coming.

The White House is expected to announce tougher sanctions on Russia Tuesday following criticism from some lawmakers that sanctions President Joe Biden announced Monday were limited.

U.K. Prime Minister Boris Johnson labeled Russia's actions this morning as a "renewed invasion" and announced the U.K. was sanctioning five Russian banks and three oligarchs, while the European Union weighs another set of sanctions that would ban trading in Russian state bonds and target imports and exports with separatist entities.

Top Russian officials have dismissed the new western sanctions, with Russia’s foreign minister Sergey Lavrov in a state TV interview saying Russia was already "used to" sanctions and that it considers more sanctions would be imposed on Moscow regardless of what it does.

But in what may amount to a huge blow to Russia, Germany announced earlier that it would halt Nordstrom 2, a key gas pipeline, as NATO allies aim to pressure Putin into a pathway to diplomacy. White House press secretary Jen Psaki applauded the move and teased more U.S. measures would be coming "today."

Russian President Vladimir Putin denied Tuesday that he is seeking to rebuild the Russian empire.

In remarks ahead of his meeting with Azerbaijan’s president, Putin said he knew his recognition of two Russia-backed separatist areas in eastern Ukraine would spark such "speculation."

"I have seen speculation that Russia wants to rebuild the Russian empire in its imperial boundaries. That absolutely does not correspond to reality," Putin said.

The Russian leader insisted that his country recognizes the sovereignty of all former Soviet countries but said the situation with Ukraine is "different" because he claimed foreign countries are using Ukrainian territory to threaten Russia.

"Unfortunately the territory of that country is being used by third countries to create a threat to Russia itself. The issues is only in that," Putin said, adding that Russia's cooperation with Ukriane has disappeared due to the conflict that began between the Ukrainian military and Russia-backed separatist forces in 2014, which he described as a "coup."

-ABC News' Patrick Reevell

U.S. embassy staff who remained in Ukraine will be in the western city of Lviv during the daytime and stay in Poland each night for security reasons, amid fears of a Russian invasion, according to acting U.S. ambassador to Ukraine Kristina Kvien.

"We all heard the speech President Putin delivered yesterday," Kvien told reporters in Lviv on Tuesday. "His outrageous statements about Ukraine and the Ukrainian people were delusional, reflecting a warped vision reminiscent, not of a global leader, but of Europe's worst authoritarians."

The U.S. embassy's skeleton staff had relocated operations to Lviv from the Ukrainian capital, Kyiv. They returned to Lviv on Tuesday after staying in Poland overnight, a senior U.S. official told ABC News.

-ABC News' Martha Raddatz and Sam Sweeney

German Chancellor Olaf Scholz announced Tuesday that his country will halt its approval of the Nord Stream 2 natural gas pipeline connecting Germany to Russia, in response to Russia's recognition of two separatist areas in eastern Ukraine and amid fear of further possible aggression.

"The situation today is fundamentally different," Scholz said at a press conference in Berlin.

Scholz said he has asked Germany's Federal Ministry for Economic Affairs and Climate Action to take a step that blocks certification of the Nord Stream 2. That means the pipeline, which is already built, cannot go into operation for now.

The Nord Stream 2, a key pipeline linking Russia to Europe by circumventing Ukraine, has been highly controversial, with Germany accused of allowing Russia to construct a geopolitical weapon enabling Moscow to pressure Europe using gas supplies. Last year, Ukraine and the United States were pushing to stop the project but Germany refused.

The decision to halt the pipeline's certification serves as a major sanction against Russia amid growing fears of an invasion of neighboring Ukraine and immense pressure on Germany to act. Earlier Tuesday, Ukrainian President Zelenskyy called on Germany to include the Nord Stream 2 in Europe's sanctions on Russia.

"At this stage, in addition to initial sanctions, it is now important to prevent further escalation and thus another catastrophe," Scholz said. "That is what all our diplomatic efforts are aimed at."

The move may amount to a huge blow to Russia, which has already stoked a gas crunch in Europe by having its state-owned energy company Gazprom deliver the bare minimum of gas despite severe shortages. Gazprom has continued to do that in recent weeks and could go further, and Germany is particularly vulnerable. During a press conference last week, Scholz repeatedly refused to explicitly say if he would be willing to halt the Nord Stream 2.

However, by suspending the pipeline's certification, Germany dangles the possibility it could be resumed if Russia doesn't make further aggressions against Ukraine. It's unclear how Russia will respond to a continent that it knows is overly reliant on Russian energy.

-ABC News' Mary Bruce, Sarah Hucal, Ian Pannell and Patrick Reevell