According to article ii what is the president's main duty answer. com

I believe the answer is: to carry out laws that have been passed

The president of united states held the status as the head of the executive branches of the government.
So technically, president's main duty is to carry out the laws that made by the Congress.But since the president also held the position as the head of the country, he can still propose the type of law that should be discussed by congress and use his veto rights to reject some bills.