Joe Biden declares 'democracy has prevailed' in first Presidential speech

Joe Biden says democracy has prevailed in his first speech as the new President of the United States.

Biden was sworn into office on Thursday morning (NZ time) along with vice President Kamala Harris at an inauguration ceremony at the Capitol building attended by politicians including Barack Obama and former vice President Mike Pence.

"This is America's day. This is democracy's day," Biden told Americans.

"America has been tested and America has risen… The people, the will of the people has been heard.

"I pledge this for you - I will be a President for all Americans and I promise I will fight as hard for those that didn't support me as those who did."

He said that democracy is fragile as seen in the 2020 election, which was marred by claims of unproven voter fraud. 

Supporters of Donald Trump then descended on the Capitol on January 6 in protest of the certification of Biden's win.

"Democracy has prevailed," Biden said during his speech. 

"For now on this hallowed ground where just a few days ago violence shook this building... To carry out the peaceful transfer of power as we have for more than two centuries."

He called for unity from both Republican and Democratic supporters.

"We must fight this civil war which puts red against blue. We can do this if we open our souls instead of closing our hearts.

"Some days when you need a hand, or other days when we are called to lend a hand. If we are this, our country will be more prosperous. We are going to need all the strength we have to get through this winter."

He also thanked the presidential predecessors of both parties for being there today and "thanked them for the bottom of my heart".

"I've just taken a sacred oath both of these people have taken... But the American story doesn't depend on some of us. It depends on all of us - we the people."