In April 1847, Scott defeated a Mexican force led by Santa Anna at the Battle of Cerro Gordo, clearing the way for a march on Mexico City. In August, Scott defeated Santa Anna again at the Battle of Contreras and the Battle of Churubusco. With these victories over a larger force, Scott's army was positioned to besiege Mexico's capital. Santa Anna negotiated a truce with Scott, and the Mexican foreign minister notified Trist that they were ready to begin negotiations to end the war. However, the Mexican and American delegations remained far apart on terms; Mexico was only willing to yield portions of Alta California, and still refused to agree to the Rio Grande border. While negotiations continued, Scott captured the Mexican capital in the Battle for Mexico City.