He laid stress for the Democrats to continue their "grassroots efforts to create the America that we know can become"
He said in a capstone livestream address to his political followers that the major task they face is to make certain Trump is defeated
Sanders has also vowed to foster party unity to take on Republican nominee Donald Trump
We are going to fight hard to win the primary in Washington, DC, said Sanders
Hilary Clinton had won the Kentucky primary, held on May 17, by 1,924 votes
PM Modi, Sania Mirza and Priyanka Chopra are also among the probable contenders named by the magazine for its annual list
Sanders still faces a steep climb to overtake Clinton but the big victories in the West generated more momentum for his upstart campaign
Sanders, 74, won Washington state by getting more than 72% of the total votes counted
Bernie Sanders is hopeful that he could pick up wins in Washington, Alaska and Hawaii
Clinton has so far won 12 States, while Bernie Sanders has won nine States
Cruz scored decisive wins in the Kansas and Maine caucuses while Sanders won in Kansas and Nebraska
The Vermont senator had lost significant momentum to the former US secretary of state following last week's Super Tuesday vote
Bernie Sanders may have found his Fed chief