US Democratic presidential candidate Hillary Clinton has courted the critical black vote as she met with civil rights leaders in New York and promised in a speech to tackle "very real barriers" confronting African-Americans.
Clinton is seeking to maintain her lead among black voters over US Senator Bernie Sanders of Vermont, her rival for the Democratic nomination for the November 8 election to succeed Democrat Barack Obama, the first black US president.
The Clinton campaign said last week: "It will be very difficult, if not impossible, for a Democrat to win the nomination without strong levels of support among African-American and Hispanic voters."
Clinton's status as the Democratic front-runner was jolted this month when the former secretary of state beat Sanders by less than a percentage point in Iowa's caucuses and lost to him by more than 20 points in the New Hampshire primary.
More than 90 per cent of people in those states are white.
Clinton met for more than two hours on Tuesday with a half-dozen civil rights leaders at the New York headquarters of the National Urban League.
"I thought that the secretary demonstrated an ease and familiarity with many of the issues we discussed this morning," National Urban League President Marc Morial said afterwards.
The Reverend Al Sharpton joked with Clinton in the corridors afterwards, suggesting to reporters he had told her which candidate he would endorse.
"My lips are sealed!" Clinton replied with a smile.
At a news conference later, Sharpton said Clinton was "candid and open," but he added he had yet to decide who to support and that no candidate should take the support of black voters for granted.
Clinton's campaign team has argued that Sanders' growing support among Democrats will likely falter as voting for a party nominee moves to more racially diverse states in the coming weeks.
Opinion polls show Clinton with a strong lead over Sanders in South Carolina, where blacks are likely to make up more than half the voters in the state's Democratic primary on February 27.
Later on Tuesday, Clinton, a former US senator from New York, gave a speech in the historically black New York City neighbourhood of Harlem on breaking down the barriers that black families face.
She was joined onstage before her remarks by New York Democratic Governor Andrew Cuomo, New York City Mayor Bill de Blasio and Eric Holder, the first black US attorney general.
"There are still very real barriers holding back African-Americans from fully participating in our economy and our society," Clinton said, citing disparities between blacks and whites in earnings, health and criminal sentencing.
She said that if elected, she would spend $US2 billion ($A2.82 billion) to encourage public school districts with a high number of troubled students to hire social workers and other experts to help young people before they get entangled in the criminal justice system.
