A Panamanian national holiday remembering the killing of 21 protesters by police and U.S. troops in 1964 is taking on new resonance this year as U.S. President-elect Donald Trump threatens to take back control of the Panama Canal.

Hundreds of Panamanians marched on Thursday to mark the anniversary of a deadly uprising against U.S. control of the Panama Canal in 1964, with some protesters burning an effigy of President-elect Donald Trump who has threatened to retake the vital global waterway.

Treaties ratified by the Senate in 1978 established permanent neutrality, but some Republicans regret that decision.

PRESIDENT JIMMY CARTER said that returning control of the Panama Canal to the government of Panama would open global trade opportunities, reduce anti-American feeling in Latin America and boost his country’s prestige.

For weeks, Donald Trump has been stating his intention to take control of the Panama Canal, a critical 51-mile long waterway that connects the Atlantic and Pacific oceans.

The Panama Canal Authority chief dismissed President-elect Trump’s claims that China is controlling the trade route and criticized his comments about fees. Ricaurte Vásquez Morales told The Wall

The leader of the Panama Canal Authority denied President-elect Donald Trump’s claims that China is controlling the vital trade route and said Trump’s suggestion that U.S. ships get preferential rates “will lead to chaos.

Panama rejected suggestions of Chinese influence over its canal and dismissed threats of possible US military action on January 7, after President-elect Donald Trump refused to rule out force to regain control of the strategic waterway.