Bernie Sanders extended a string of victories today by winning the US presidential Democratic nominating contest in Wyoming, beating rival Hillary Clinton as they gear up for a crucial match-up in New York.

Mr Sanders, a US senator from Vermont, is trying to chip away at Ms Clinton's sizeable lead in the number of delegates needed to secure the party's nomination.

However, Wyoming's 14 Democratic delegates - fewer than any other state - will be awarded proportionally and will do little to help Mr Sanders close the gap.

Going into Wyoming, Ms Clinton had more than half of the 2,383 delegates needed to win the nomination. Mr Sanders trailed her by 250 pledged delegates.

Ms Clinton's lead widens when super delegates, Democratic leaders who can decide whom to support at the party's July convention, are included in the tallies.

Ms Clinton and Mr Sanders both spent today campaigning in New York, which holds its contest on 19 April and where a total of 291 delegates are up for grabs.

Ms Clinton, a former secretary of state, considers New York her home turf. She represented the state as a US senator and has headquartered her campaign in Brooklyn.

Mr Sanders has reminded voters he was born and raised in Brooklyn. Recent polls have shown Ms Clinton more than 10 points ahead in the state.

After a back-and-forth about who was most qualified to be president, Ms Clinton and Mr Sanders dialed back their criticism of one another yesterday.

"I think this has all been pretty silly," Ms Clinton told reporters at a campaign stop in Buffalo, in upstate New York.

"He made his comments and there was no basis for them. It was completely a misrepresentation, and he seemed to take them back today."

In Wyoming's Republican contest last month, US Senator Ted Cruz of Texas beat New York billionaire Donald Trump, the party's front-runner.

Mr Cruz is trying to block Mr Trump from receiving enough delegates to win the nomination outright, which would lead to a contested convention in July.

A new Reuters/Ipsos poll shows that a third of Mr Trump's Republican supporters could consider abandoning the party's candidate if Mr Trump is denied the nomination at a contested convention.