Just ahead of U.S. President Donald Trump's tweet early Thursday warning that a military attack on Syria will take place at some point in the future—either "soon or not so soon"—a group of international law experts declared in a statement that any such attack would amount to an illegal act of aggression, which has been defined as "the supreme international crime."

Never said when an attack on Syria would take place. Could be very soon or not so soon at all! In any event, the United States, under my Administration, has done a great job of ridding the region of ISIS. Where is our “Thank you America?” — Donald J. Trump (@realDonaldTrump) April 12, 2018

"The unlawful killing of any human being without legal justification, under every legal system, is murder," the experts said. "And an act of violence committed by one government against another government, without lawful justification, amounts to the crime of aggression: the supreme international crime which carries with it the evil of every other international crime, as noted by the International Military Tribunal at Nuremberg in 1946."

"We urge the United States to abide by its commitment to the rule of international law and to seek to resolve its disputes through peaceful means."

"Our point is a simple one: the only way to resolve the Syrian crisis is through commitment to well-settled principles of international legal norms," the experts continued. "We urge the United States to abide by its commitment to the rule of international law and to seek to resolve its disputes through peaceful means."

In addition to violating international law, American members of Congress have argued in recent days that any unilateral attack on Syria would also violate the U.S. Constitution.

"President Trump has no legal authority for broadening the war in Syria," Sen. Bernie Sanders (I-Vt.) said in a statement on Wednesday. "It is Congress, not the president, who determines whether our country goes to war, and Congress must not abdicate that responsibility."

Nonetheless, Trump—with the corporate media dutifully beating the war drums in the background—has continued to escalate tensions and threaten missile strikes against Syria on Twitter, stoking fears of a direct confrontation with Russia and Iran.

As Common Dreams reported, Trump on Wednesday directly warned Russia to "get ready" because missiles "will be coming" at Syria.

Read the international law experts' full statement against Trump's push for military action below: