who didn't honor an agreement made with Polk to end the war and led the troops in a battle at Buena Vista, which they lost

Antonio Lopez de Santa Anna was the one who refused to honor the agreement made with the United States President, James Polk to end the war, and led the Mexican troops in a battle against the U. S Army in 1847. The war which is popularly known as the Mexican-America war was lost by the Mexican troops led by Santa Anna to Major General Zachary Taylor's army.

The Battle which was fought at Buena Vista was a fight for more landmass. After the defeat of the Mexican troops by General Taylor, the U. S troops did not pursue the Mexican troops as they retreated by rather allowed them to retreat with launching any offensive against them. After General Taylor's victory at the war, he join politics and won the election as the United States President.