Rep. Joaquin Castro (D-TX) on Sunday said President Donald Trump’s tweets about North Korea’s nuclear and missile tests have not “been helpful” and have “escalated the tension.”

“I don’t think that it’s been helpful,” Castro said on ABC’s “This Week” of Trump’s harsher rhetoric on the subject. “I don’t think that it’s helpful to get into a Twitter shouting match with a 32-year-old dictator, Kim Jong Un, in North Korea.”

He said Trump has “escalated the tension in the situation.”

“He needs to let his diplomats and his military generals and others handle the situation,” Castro said.

Rep. Joaquin Castro: "I don't think it's helpful to get into a Twitter shouting match with a 32-year-old dictator." https://t.co/OAyzQiLnFp pic.twitter.com/xQJAwPTtqB — ABC News (@ABC) September 3, 2017

North Korean state-run media on Saturday claimed that leader Kim Jong-un inspected the loading of a hydrogen bomb into a new intercontinental ballistic missile.

Trump responded to those reports of what he called “a major Nuclear Test” on Sunday in a series of tweets where he called North Korea “a rogue nation” and “very hostile and dangerous to the United States” and chastised South Korea for its “talk of appeasement.”