WASHINGTON, April 26 (Xinhua) -- Republican Donald Trump won sweeping victories in the primaries across five northeastern U.S. states on Tuesday night, making a contested Republican National Convention even less likely, multiple media outlets reported.

Shortly after all polls closed at 8 p.m. local time, Trump was projected winner in the Republican primaries in Maryland, Connecticut,Delaware, Rhode Island and delegate-rich Pennsylvania.

Trump's win gives him 17 delegates out of a total of 71 in Pennsylvania. The remaining 54 are unbound and free to support any candidate they like at the Republican National Convention in July.

Earlier on the day, the biggest Never Trump super-PAC claimed it can still topple the New York billionaire even if he wins all the delegates in all these states.

His rivals, Ted Cruz and John Kasich, declared on Sunday night, less than 48 hours to the Tuesday primaries, to join forces in a desperate bid to deny Trump the nomination. Both of them are already "mathematically dead" in the quest for a majority of delegates.

Trump said on Monday the partnership of Cruz and Kasich "makes them both look weak" and that it could backfire in upcoming races.