French President Emmanuel Macron and German Chancellor Angela Merkel will hold talks with Ukrainian President Volodymyr Zelenskiy on April 16 in a show of support for Kyiv amid concerns about a buildup of Russian troops along the border with Ukraine and in occupied Crimea.

Macron will receive Zelenskiy for lunch in Paris and both leaders will then talk with Merkel on a videoconference call, the French presidency said.

“Ukraine’s sovereignty is under threat,” Macron’s office said. “All our work is aimed at avoiding an escalation and defusing tensions.”

Zelenskiy said the discussions in Paris will help prepare so-called Normandy Format talks involving the leaders of Ukraine, Russia, France, and Germany to try to resolve the Ukraine conflict. France and Germany have been mediators in the conflict since 2015.

Recent photographs, video, and other data suggest major movements of Russian armed units toward or near Ukraine’s border and into Crimea, fueling concerns that Russia is preparing to send forces into Ukraine.

The United States and NATO have described it as the largest Russian military buildup since 2014, when Moscow illegally annexed Crimea and backed separatists in the east of Ukraine in a conflict that has killed more than 13,000 people.

Zelenskiy’s meeting with Macron and Merkel comes after Ukrainian Foreign Minister Dmytro Kuleba called for stronger Western backing, saying that “words of support aren’t enough.”

Kuleba, speaking on April 15 after talks in Kyiv with his counterparts from Estonia, Latvia, and Lithuania, asked the Baltic states to reach out to other European Union and NATO members about offering “practical assistance” to Kyiv.

Kuleba accused Moscow of “openly threatening Ukraine with war and the destruction of Ukrainian statehood” and said it was necessary to show Russia that its actions in eastern Ukraine could have “very painful” consequences.

“The red line of Ukraine is the state border. If Russia crosses the red line, then it will have to suffer,” he warned.

Russia’s Defense Ministry has said the troops are merely responding to “threatening” actions by the NATO alliance and participating in military drills.

U.S. President Joe Biden and Merkel earlier this week called on Russia to reduce its border deployment.

The call came after German Defense Minister Annegret Kramp-Karrenbauer on April 14 accused Russia of seeking provocation with its troop buildup.

“My impression is that the Russian side is trying everything to provoke a reaction,” Kramp-Karrenbauer said.

With reporting by AFP