WASHINGTON — Eighteen Senate Democrats are warning U.S. President Donald Trump that he lacks the legal authority to pre-emptively strike North Korea.

“Like many, we are deeply concerned about the potential consequences of a preemptive military strike on North Korea and the risks of miscalculation and retaliation,” the senators said in a letter to Trump on Monday.

Weighing in on reports the Trump administration is considering limited, pre-emptive “bloody nose” attacks to rid Pyongyang of its nuclear program, the lawmakers said such a strike would be “an enormous gamble” that North Korea would not escalate.

“[W]ithout congressional authorization a preventative or preemptive U.S. military strike would lack either a Constitutional basis or legal authority,” reads the letter, led by New Mexico Sen. Martin Heinrich, a member of the Senate Armed Services Committee.

Trump reportedly dropped his pick for ambassador to South Korea, Victor Cha, over Cha’s objections to such an attack — a move the lawmakers called “disturbing.” Seoul had been notified of the administration’s intent to pick, who had reportedly undergone thorough vetting for months.

Senate Foreign Relations Committee ranking member Ben Cardin, D-Md., and Senate Armed Services Committee ranking member Jack Reed, D-R.I., signed the letter, which was first reported by The Washington Post.

“Tensions on the Korean Peninsula are as high as they have ever been, and the Olympics are fast approaching,” the letter reads. “While we must always be ready to respond with decisive action to a North Korean provocation, it would be extremely irresponsible to instigate military conflict prior to exhausting every diplomatic option.”

The idea of a limited strike on North Korea has, in recent days, drawn criticism from former Defense Secretary Chuck Hagel and other Democratic lawmakers, who say such an attack could spark a devastating war.

Former Secretary of State Henry Kissinger warned in recent congressional testimony that if America and China let North Korea keep its nuclear weapons, it will spur other countries to seek them, creating unprecedented complications for geopolitics.