Washington: President Donald Trump assumed power Friday with a fiercely nationalistic vow to put "America first," taking a stinging swipe at the legacy of his predecessor hours after reciting the oath of office.

Hundreds of thousands of people stood on the rain-splattered National Mall to see the 70-year-old Republican billionaire be sworn in, and deliver a stridently populist call-to-arms.

Trump promised to lift up the nation’s disenfranchised and those who felt betrayed by the political elites, declaring with vindication that “the forgotten men and women of our country will be forgotten no longer.”

“From this day forward, a new vision will govern our land,” Trump said, promising an end to business-as-usual in Washington. “From this moment on, it’s going to be only America First.”

He also said that he will follow two simple rules — Buy American, Hire American.

Adhering to his vow to immediately start dismantling the healthcare reforms passed by outgoing president Barack Obama, Trump signed his first executive order in the Oval Office, targeting Obamacare.

Hundreds of thousands of people stood on the rain-splattered National Mall to see the 70-year-old Republican billionaire be sworn in, and deliver a stridently populist call-to-arms.

Trump promised to lift up the nation’s disenfranchised and those who felt betrayed by the political elites, declaring with vindication that “the forgotten men and women of our country will be forgotten no longer.”

“From this day forward, a new vision will govern our land,” Trump said, promising an end to business-as-usual in Washington. “From this moment on, it’s going to be only America First.”

He also said that he will follow two simple rules — Buy American, Hire American.

Adhering to his vow to immediately start dismantling the healthcare reforms passed by outgoing president Barack Obama, Trump signed his first executive order in the Oval Office, targeting Obamacare.