On Tuesday, French President Emmanuel Macron traveled to Kyiv, Ukraine’s capital, to continue his diplomatic efforts to ease the crisis there, a day after hours of discussions with Russian President Vladimir Putin offered no apparent headway.

As worries of a Russian invasion grow, Macron met with Ukrainian President Volodymyr Zelenskyy. Moscow has amassed nearly 100,000 troops on Ukraine’s borders, but claims no intention of attacking.

The Kremlin wants assurances from the West that NATO would not admit Ukraine and other former Soviet republics as members, that it will suspend weapon deployments in the region, and that it will withdraw its military from Eastern Europe – demands that the US and NATO dismiss as unrealistic.

In recent weeks, Western leaders have engaged in a flurry of diplomacy in the hopes of de-escalating tensions and averting a strike. In the midst of military training in Russia and Belarus, high-level conversations have taken place. Six huge landing ships are headed from the Mediterranean to the Black Sea for training, according to Russia’s Defense Ministry.

Macron’s Monday conversations with Putin lasted more than five hours, and he told reporters that they allowed him to assure that “no degradation and no (further) escalation” occurred.

He stated that he did not anticipate Putin to make any “gestures,” and that his goal was to “avoid an escalation and open up new possibilities.” … That goal has been accomplished.”

After the meeting, Putin claimed that the US and NATO had ignored Moscow’s requests, but that he was willing to continue the talks.

NATO, US, and European officials have categorically rejected proposals that they say go against NATO’s basic values, such as closing the door to Ukraine or other potential members, but they have pledged to discuss other Russian security concerns in Europe.

Should Kyiv seek to recover the Crimean Peninsula, which Moscow annexed in 2014, Putin warned that Ukraine’s membership in NATO might spark a conflict between Russia and NATO. He said that in such situation, European countries will be pulled into a military battle with Russia in which “no one will win.”

Although US President Joe Biden has stated that Ukraine joining NATO “in the short term” is “not very probable,” he, along with other NATO member states and NATO itself, refuse to rule out Ukraine joining the organization at some point in the future.

On Monday, Biden met with German Chancellor Olaf Scholz in Washington, and the two will fly to Kyiv and Moscow on February 14-15.

“If Russia invades, it means tanks and troops crossing the border of Ukraine again,” Biden said, referring to the Nord Stream 2 Russia-Germany gas pipeline, which has been constructed but is not yet operational. Stopping the pipeline’s functioning would be bad for Russia’s economy, but it would also pose supply issues for Germany.

In the event of an invasion, Scholz cautioned Moscow that “a lot more may happen than they’ve possibly estimated with themselves.”

Boris Johnson, the British Prime Minister, cautioned Russia that an invasion of Ukraine would simply strengthen NATO, but he still hopes that “principled and resolute diplomacy” may calm the problem.

Johnson encouraged partners to finish measures for harsh economic penalties that would take effect if Russia crossed the border into Ukraine, according to The Times of London.

As he prepared to visit the Lithuanian prime minister in London on Tuesday to demonstrate solidarity for the Baltic states, he said the UK is ready to reinforce NATO soldiers in Latvia and Estonia.

Johnson suggested RAF Typhoon fighter jets and Royal Navy warships may be sent to southern Europe. The United Kingdom said on Monday that it will send 350 troops to Poland to help NATO’s eastern flank. Ukraine has already received anti-tank weaponry.

More than 100 US military personnel have arrived in Romania ahead of a deployment of approximately 1,000 NATO forces planned in the next days, according to Romanian Defense Minister Vasile Dincu, who also stated that “the remainder of the troops would come soon.”

According to US authorities, roughly 1,000 NATO troops would be dispatched from Germany to Romania, which has been a NATO member since 2004. Romania shares a northern border with Ukraine.

Officials in the United States have warned that an invasion of Ukraine is coming – predictions that Moscow has dismissed, accusing Washington of inflaming tensions.

Since 2014, when Ukraine’s Kremlin-friendly president was deposed, Moscow grabbed Crimea, and subsequently backed a separatist rebellion in the country’s east, the two countries have been at odds. Over 14,000 people have been died in conflict between Russia-backed separatists and Ukrainian forces.

In 2015, France and Germany aided in the brokering of the Minsk accords, which ceased large-scale fighting but did not result in a political resolution to the war. The Kremlin has accused Kyiv of undermining the agreement, and Ukrainian authorities have recently stated that executing it would be detrimental to the country.

Putin said after meeting Macron that some of the French president’s recommendations may serve as a framework for resolving the separatist crisis, without going into detail, and that they planned to communicate by phone following Macron’s visit to Kyiv.

Dmytro Kuleba, Ukraine’s foreign minister, said Kyiv was “looking forward to the signals” Macron delivered from Moscow and was “ready to talks,” but would not violate its own “red lines.”