Ukraine's President Volodymyr Zelenskyy said he has spoken with U.S. President Donald Trump for the second time in two days, discussing strengthening of Kyiv's air defense, resilience and long-range capabilities, Zelenskyy said on Sunday.

"We also discussed many details related to the energy sector. President Trump is well informed about everything that is happening. We agreed to continue our dialog, and our teams are doing their preparations," Zelenskyy said on X.

The Kremlin said on Sunday Russia was deeply concerned about the possibility of the U.S. supplying Tomahawk missiles to Ukraine, warning that the war had reached a dramatic moment with escalation from all sides.

Trump said on Monday that before agreeing to provide Tomahawks, he would want to know what Ukraine planned to do with them because he did not want to escalate the war.