Americans react after major news organisations called the election for Joe Biden (Image: EPA/Will Oliver)

Joe Biden will be the 46th president of the United States after finally securing sufficient electoral college votes following a marathon count that delivered him the state of Pennsylvania, triggering celebrations across the United States.

At around 11.25 on Saturday morning, US time, networks and AP began calling Pennsylvania for the former vice-president, who currently leads there by nearly 30,000 votes, handing Biden the 270 electoral college votes he needs for victory.

As President Donald Trump raged in the White House about a rigged election and electoral fraud, his lead in key battleground states steadily evaporated over the last three days with the counting of mail and pre-poll ballots, despite extensive and futile Trump efforts to convince courts to prevent further counting.