Donald Trump has arrived in Vietnam for the start of his second summit with the leader of North Korea. But days before he left on that trip, a trio of House national-security chairmen told Trump to come clean on information surrounding his diplomacy with Kim Jong Un.

Congress is so in the dark, they say, that they still aren’t up to speed on last year’s historic summit between Trump and Kim, which was the first such encounter between a North Korean leader and a sitting president of the United States.

The bilateral meetings are ostensibly about de-nuclearizing North Korea, which for decades, has been working to become a nuclear power.

North Korea has become both a pariah and highly isolated nation since the end of the 1950-1953 Korean War. The North is the target of strict and crippling economic sanctions.

Although a cease-fire ended hostilities of the Korean War, there was no armistice which means North and South Korea remain, technically, in a state of war more than 60 years later.

In a letter to Trump, Chairmen Eliot Engel, of the Committee on Foreign Affairs, Adam Smith of the Committee on Armed Services, and Adam Schiff of the Permanent Select Committee on Intelligence emphasized that the administration has failed to brief Congress on the negotiations since the June 2018 Singapore summit, has cut off Congress’s access to intelligence regarding North Korea’s nuclear and conventional weapons, and has ignored law requiring a report to Congress on North Korea’s nuclear program.

The lawmakers also raised the growing concern that Trump and his top intelligence officials appear at odds when it comes to the progress being made on this matter.

“We are perplexed and troubled by the growing disconnect between the Intelligence Community’s assessment and your administration’s statements about Kim Jong Un’s actions, commitments, and intentions,” the chairmen write. “Furthermore, our ability to conduct oversight of U.S. policy toward North Korea on behalf of the American people has been inappropriately curtailed by your administration’s unwillingness to share information with Congress.”