On 16 June, Bernie Sanders promised to work with presumptive Democratic presidential nominee Hillary Clinton to beat Republican Donald Trump in the upcoming US election to be held on 8 November.
Even though he pledged support to Clinton, he hasn't been formally pull out from the race.
Focusing at a major 'political task' ahead, Sanders said it is the party's duty to ensure that Trump loses in the race to the White House.
"The major political task that we face in the next five months is to make certain that Donald Trump is defeated and defeated badly, and I personally intend to begin my role in that process in a very short period of time," the US senator from Vermont said in a speech broadcast from his hometown of Burlington.
"I also look forward to working with Secretary Clinton to transform the Democratic Party so that it becomes a party of working people and young people, and not just wealthy campaign contributors," he added.
He also said that, "We must continue our grass-roots efforts to create the America that we know we can become. And we must take that energy into the Democratic National Convention on July 25 in Philadelphia where we will have more than 1,900 delegates."
Sanders has been in pressure of pulling out from Democrats since Clinton bagged the party nomination last week.