While Trump was taking oath as 45th US President, Twitter users were having the time of their life with funny memes, reactions, and quotes. We take a look at some of the good ones for a good hearty laugh.

Donald Trump has sworn in as 45th president of the United States and the world is already thinking. Newsheads take a look at what leaders across the world are saying about America's new 'controversial' leader.

"This has been the privilege of my life, and I know I speak for Michelle as well," EFE news quoted Obama as saying with former First Lady Michelle Obama at his side on the tarmac at Joint Base Andrews, just outside Washington.

The dollar index, which measures the greenback against six major peers, decreased 0.37 per cent at 100.78 in late trading on Friday.

Trump's White House new website maintains a page where it says the visitor records will be posted, The Washington Times reported.

The website was transformed to remove all traces of former President Barack Obama's climate change initiatives and to reinforce border protection policies.

The new head of state put his signature to a measure passed by Congress exempting Trump's nominee for Defence Secretary, retired Gen. James Mattis, from a law requiring a person to be out of the armed forces for seven years prior to becoming head of the Pentagon, EFE news reported.

Twitter changed the accounts almost immediately after Trump was sworn in as the 45th President of the US. Meanwhile, Barack Obama became @POTUS44 and Michelle @FLOTUS44.

Following the acts of violence, helmeted police chased away protesters with batons, hose them with pepper spray and fire flash bangs.

The verified handle, which has been used liberally by Trump to attack those he perceives as hostile to him, has over 20 million followers, and he has posted over 34,000 tweets.