U.S. President Donald Trump said on Thursday he received a note from North Korean leader Kim Jong Un dated July 6 in which Kim said he believed their efforts to improve relations will succeed.

"A very nice note from Chairman Kim of North Korea. Great progress being made!" Trump said in a Twitter post that included an image of the letter and an English-language translation of it.

"I firmly believe that the strong will, sincere efforts and unique approach of myself and Your Excellency Mr. President aimed at opening up a new future between the DPRK and the U.S. will surely come to fruition," Kim said, according to the translation, referring to North Korea by an acronym.

Kim said he hoped for "practical actions" in the future, but offered no specifics.