North Korean leader Kim Jong Un visits the Pyongyang Trolley Bus Factory and the Bus Repair Factory in Pyongyang, North Korea in this photo released August 4, 2018 by North Korea's Korean Central News Agency. KCNA/ via REUTERS

JAKARTA (Reuters) - A U.S. diplomat handed over a letter for North Korean leader Kim Jong Un from U.S. President Donald Trump to North Korea’s foreign minister at a meeting Singapore on Saturday, a U.S. State Department spokeswoman said.

Sung Kim, the U.S. ambassador to the Philippines, who has played a prominent role in U.S. talks with North Korea, handed the letter to Ri Yong Ho on the sidelines of a regional meeting, State Department spokeswoman Heather Nauert said.

She said the letter was a response to one from Kim Jong Un to Trump.

In Singapore, U.S. Secretary of State Mike Pompeo and Ri shook hands and exchanged words and smiles at a Southeast Asian security forum, but had no formal meeting, Nauert said. Nauert said Pompeo told Ri: “We should meet again soon.”She said Ri replied: “I agree, there are many productive conversations to be had.”