Ukrainian President Volodymyr Zelensky revealed Monday that he is pushing the United States to make security guarantees for his country beyond what President Donald Trump has said he would agree to.

In a series of social media posts, Zelensky disclosed more details about negotiations he held with Trump over the weekend that centered on a 20-point deal seeking to end Ukraine’s war with Russia. Security guarantees, as well as territorial concessions, have formed the crux of the peace talks the U.S. is brokering, which have spanned months.