Washington, Jan 23 (IANS): Whistle-blower group WikiLeaks called out US President Donald Trump for refusing to release his tax returns, after a senior adviser said definitively that the New York-mogul would not be publicly disclosing the documents.

"Trump's breach of promise over the release of his tax returns is even more gratuitous than Clinton concealing her Goldman Sachs transcripts," WikiLeaks said on Sunday.

The group also encouraged the leak of the documents, Politico reported.

"Trump Counsellor Kellyanne Conway stated today (Sunday) that Trump will not release his tax returns. Send them to: https://wikileaks.org/#submit so we can."

Earlier on Sunday, Conway firmly said Trump will not be releasing his tax returns. Before he took office, Trump had used a different line, saying he could not yet disclose the documents because they were under a routine audit.

In an interview to ABC News, Conway said the controversy over the tax returns was an attempt to re-litigate the presidential campaign.

"The White House response is that he's not going to release his tax returns," Conway said.

"We litigated this all through the election. People didn't care," Conway said. "They voted for him, and let me make this very clear: Most Americans ... are very focused on what their tax returns will look like while President Trump is in office, not what his look like."

Calls for Trump to disclose his tax returns have continued since his election, with critics saying the move would clarify whether he has any foreign conflicts of interest.