Donald Trump has swept primaries in another five US states, moving closer to winning the Republican presidential nomination as he easily defeated rivals Ted Cruz and John Kasich.
Trump, who gained momentum after losing the Wisconsin primary to Cruz on April 5, scored victories in Pennsylvania, Maryland, Connecticut, Rhode Island and Delaware, US television networks projected. His margin of victory in each state appeared to be even larger than in his home state of New York a week ago.
Democratic frontrunner Hillary Clinton won in Maryland, Delaware, Connecticut and Pennsylvania, while her challenger Bernie Sanders won Rhode Island.
Although the race remains fluid, Trump's wins made it less likely that Republicans would choose their nominee for the November 8 presidential election at a contested convention in July in Cleveland, an outcome seen by Cruz and Kasich as their only chance at the nomination.
"They should drop out because frankly they have no path to victory," Trump told media at a magazine event in New York honouring influential Americans.
Cruz, already looking ahead to Indiana's Republican primary on May 3, addressed a crowd in that state just as polls were closing in the Northeastern states.
"I got good news for you: Tonight, this campaign moves back to more favourable terrain," the US senator from Texas said in Knightstown, Indiana, inside the high school gymnasium made famous by the underdog movie, Hoosiers.
Clinton's strong showing in the Democratic race added to the pressure on Sanders to get out of the race or ease his criticism of her.
Before today's outcome, the former secretary of state had an almost insurmountable lead of 275 pledged delegates heading into Tuesday's (local time) contests, and Senate Democratic leader Harry Reid told reporters he did not think Sanders, a US senator from Vermont, had a realistic path to winning the nomination.
Sanders, speaking to a big crowd in Huntington, West Virginia, showed no signs of getting out of the race and said he was shedding light on inconvenient truths about how hard life was these days for some Americans.
"The reason that we are generating this enthusiasm is because we are doing something very unusual in contemporary politics. We are telling the truth," he said.
A total of 118 pledged Republican delegates were at stake in addition to 54 unbound Pennsylvania delegates.
Cruz and Kasich, the Ohio governor, have formed an anti-Trump alliance in an effort to stop the New York billionaire from reaching a first-ballot victory at the July convention.
Former Republican presidential candidate Ben Carson, a Trump supporter, said the deal between Kasich and Cruz would backfire because it smacked of backroom politics.