President Donald Trump spoke with Russian leader Vladimir Putin ahead of his meeting with Ukrainian leader Volodymyr Zelenskyy to discuss a peace plan for the war-torn nation.

Trump said in a Dec. 28 social media post that the call with Putin was “good and very productive.”

The president is trying to hammer out a deal to end nearly four years of fighting after Russia invaded Ukraine, with Zelenskyy arriving at Trump’s Mar-a-Lago resort Dec. 28 to discuss the 20-point plan that American and Ukrainian leaders have been negotiating.

The peace plan would implement security guarantees to protect Ukraine from further attacks, allow the country to keep an 800,000-troop military, provide help for rebuilding the nation's economy and craft a plan for membership in the European Union.

Zelenskyy said in a Dec. 27 social media post that the security guarantees are the most important aspect of the potential deal.