Donald Trump Jr. released a series of screenshots on Monday showing Twitter messages between himself and WikiLeaks sent during the final stages of the 2016 presidential election.

In the exchange, WikiLeaks asked Trump Jr., the oldest son of US President Donald Trump, to push an article critical of former Democratic presidential candidate Hilary Clinton. It also tried to convince Trump Jr. to leak his father's tax returns in order to "dramatically improve" Wikileaks' perceived impartiality.

"That means that the vast amount of stuff that we are publishing about Clinton will have much higher impact," Wikileaks told Trump Jr. in one of the messages, "because it won't be perceived as coming from a 'pro-Trump' 'pro-Russian' source, which the Clinton campaign is constantly slandering us with."

The messages began in September 2016 and ran through to the following July.

Trump Jr. released the 10 screenshots just hours after American news magazine The Atlantic first reported on them, being sure to highlight his "whopping three responses."

Read more: Donald Trump Jr. at Russia meeting sought damaging information on Hillary Clinton

In a statement, Trump Jr.'s lawyer, Alan Futerfas, said thousands of documents, including the direct messages, had been turned over to US congressional committees investigating Russian intervention during the 2016 presidential election.

"Putting aside the question as to why or by whom such documents, provided to Congress under promises of confidentiality, have been selectively leaked, we can say with confidence that we have no concerns about these documents and any questions raised about them have been easily answered in the appropriate forum," said Futerfas.

Senator Richard Blumenthal, a Democrat who sits on the Senate Judiciary Committee, called on the panel to subpoena more documents and force Trump Jr., who spoke with the committee privately in March, to publicly testify.

"There seems to be no reasonable explanation for these messages," Blumenthal said.

Vice president backtracks

US Vice President Mike Pence responded to the report quickly, issuing a statement through his press secretary that he was unaware of the correspondence.

"The Vice President was never aware of anyone associated with the campaign being in contact with Wikileaks," said spokeswoman Alyssa Farah. "He first learned of this news from a published report earlier tonight."

When asked about the Trump campaign's correspondence with WikiLeaks in October 2016, Pence had said: "Nothing can be further from the truth."

an, dv/aw (AP, AFP)