The top Democrat on the Senate Foreign Relations Committee says Congress has not granted authorization for a pre-emptive first strike on North Korea.

“Congress has not authorized the use of force, so the president does not have the authority to pre-emptively use force,” Maryland Democratic Sen. Benjamin L. Cardin said when asked during an interview about legislative proposals from some Democrats to bar nuclear strikes against Kim Jong-un.

“Now, the president’s commander-in-chief, and when he makes orders obviously the military will follow those orders. What we are saying is under no circumstances should we be using nuclear weapons and we should not be looking at a pre-emptive strike,” Cardin said. “What we should be looking at is a surge in diplomacy.”

The extent to which action the Korean peninsula would require new congressional authorization is particularly complex given that Korean War concluded with an armistice, and U.S. forces have remained in South Korea ever since.

The conversation with Cardin for an episode of C-SPAN’s Newsmakers program that will air Sunday, came just before Trump was set to depart for a 12-day trip to Asia, where North Korea’s nuclear development will be at the top of the agenda. Trump’s travel schedule includes a visit to the Korean peninsula.

In the interview, Cardin made clear that blame for the current crisis rests squarely with the North Korean government.

“They’ve created the crisis. President Trump has made it worse with his rhetoric and his statements about whether he is with or with out our allies,” Cardin said. “A military option is not where we want to be. The consequences would be catastrophic. The current trend is not acceptable. We don’t want North Korea to develop a delivery system that could reach the continental United States.”

Cardin also spoke about other regional issues that are sure to be on the agenda of Trump and Secretary of State Rex Tillerson, including the humanitarian crisis facing the Rohinga Muslim minority in Myanmar, as well as the latest effort to craft a new authorization for the use of military force to fight terrorism around the world.

Tillerson and Defense Secretary James Mattis testified Monday before the Foreign Relations Committee about administration views, and Cardin said he and Chairman Bob Corker of Tennessee would do their best to reach a consensus on finally revising the 2001 authorization.

“I want to compliment Secretary Tillerson and Secretary Mattis in their testimony before the Senate Foreign Relations Committee,” Cardin said Thursday. “It is clear to me that we cannot allow the 2001 authorization that was passed by Congress immediately after the attack on our country on Sept. 11 to be used for worldwide military campaigns against terrorists.”

Some senators want to impose significant restrictions on Trump’s ability to enter new theaters as part of the global war on terrorism, particularly when that involves U.S. ground forces. Other senators prefer a broad mandate.

Cardin is somewhere closer to the middle ground.

“We certainly don’t want to have an open-ended authorization for American ground troops to go basically anywhere in the world. It’s important that Congress replace the 2001 [law] with an authorization that makes sense,” Cardin said. “Sen. Corker and I are going to try and work together to come to an agreement on this. It’s not going to be easy.”