WASHINGTON: Republican presidential nominee Donald Trump, one of the leaders of the "birther" movement that questioned President Barack Obama's US citizenship, believes Obama was born in the United States, the Trump campaign said in a statement on Thursday.

In an interview with the Washington Post released earlier in the day, Trump declined to say whether he believed Obama was born in Hawaii.

"I'll answer that question at the right time. I just don't want to answer it yet," Trump told the newspaper.

Those comments drew criticism from Democratic presidential candidate Hillary Clinton, who expressed dismay at Trump's response during remarks to a gathering of Hispanic leaders in Washington.

"He still wouldn't say Hawaii. He still wouldn't say America. This man wants to be our next president?" Clinton said.

"When will he stop this ugliness, this bigotry? Now he's tried to reset himself and his campaign many times. This is the best he can do. This is who he is," she said.

A few years into his presidency, Obama, the first African American to win the White House, released a longer version of his birth certificate to answer those who suggested he was not US born.

"In 2011, Mr. Trump was finally able to bring this ugly incident to its conclusion by successfully compelling President Obama to release his birth certificate," Trump senior communications advisor Jason Miller said in a statement late on Thursday.

"Having successfully obtained President Obama's birth certificate when others could not, Mr. Trump believes that President Obama was born in the United States," he said.

Trump has been trying to drum up support among black voters, who overwhelmingly supported Obama in his 2008 and 2012 elections. Many African Americans object to Trump's involvement in the "birther" movement and the implication that Obama's presidency was illegitimate.