Colombian President Juan Manual Santos said Saturday he denied the resignation of his foreign and defense ministers, but vowed major policy changes.

Santos, who is shuffling his cabinet as he battles a slumping approval rating, said Maria Angela Holguin will keep her post as diplomatic chief, while Juan Carlos Pinzon will stay on as defense minister.

Santos promised a "180-degree change" in the country's foreign policy, including resetting ties with Venezuela and Ecuador.

He also pointed to recent military successes in the fight against rebels of the Revolutionary Armed Forces of Colombia (FARC), but added that there were still "problems that needed to be resolved" as concerns security.

Speaking in Tolima department, the president also said that on Friday, he had accepted the resignation of transportation chief Miguel Penalosa, who has been under investigation for improper contracting procedures.

All 16 cabinet ministers resigned on Wednesday, halfway through Santos's mandate.

Santos, who took office in August 2010, had a 70 percent approval rating a year ago, but that figure has plummeted to 45 percent.