U.S. President Barack Obama says major changes to the U.S. educational system are needed in order to properly prepare the next generation of American students.

In his first big speech on education in Washington Tuesday, Obama emphasized the importance of education in the 21st century, saying the future belongs to the nations with the most comprehensive education policies.

The U.S. president stressed the need not only to expand effective after-school programs, but to rethink the school calendar, noting that each year children in the U.S. spend over a month less in school than children in South Korea.

Obama added that the quality of U.S. education needs to be enhanced in order to overcome the global financial crisis.

He called on Americans to commit to at least one year or more of higher education or career training, with the goal of having the highest proportion of college graduates in the world by the year 2020.