Clinton all but secures nomination, Trump advances lead in primaries

Hillary Clinton and Donald Trump were a giant step closer toward securing their parties' presidential nominations with powerful wins in a string of primary wins in the U.S. Northeast.

Barring a dramatic turn of events, Clinton has now cleared the way to become the Democratic nominee in the November presidential election, which would make her the first woman in U.S. history to reach that milestone.

The former secretary of state won four out of five primaries April 27 in Connecticut, Delaware, Maryland and the night's big prize, the battleground state of Pennsylvania.

She conceded only the small state of Rhode Island to rival Bernie Sanders in a near sweep that gives her an almost insurmountable delegate lead.

Clinton now has 2,168 delegates, including more than 500 "super-delegates," against Sanders's 1,401, with about 1,000 more to be distributed in the 14 remaining nominating races.

"What a great night," Clinton told a thrilled crowd of supporters in Philadelphia, Pennsylvania.

The 68-year-old former first lady telegraphed her eagerness to shift toward the general election and a showdown with Republicans.

"Let's go forward, let's win the nomination, and in July let's return as a unified party," she said.

Clinton's strong showing heaps pressure on the well-funded Sanders, a self-declared democratic socialist senator from Vermont, even as he has vowed to fight on until the California primary on June 7.

"The people in every state in this country should have the right to determine who they want as president and what the agenda of the Democratic Party should be. That's why we are in this race until the last vote is cast," Sanders said in a statement.

"That is why this campaign is...