Donald Trump Jr has been forced to release damning emails that reveal he eagerly embraced what he was told was a Russian government attempt to damage Hillary Clinton’s election campaign.

The stunning disclosure raised questions over whether campaign laws were broken and why senior Trump associates failed to report a hostile act by a foreign power.

The emails show music promoter Rob Goldstone telling the future US president’s son that “the crown prosecutor of Russia” had offered “to provide the Trump campaign with some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father”.

British-born Goldstone adds in the exchange of 3 June 2016: “This is obviously very high level and sensitive information but is part of Russia and its government’s support for Mr Trump.”

Seventeen minutes later, Trump Jr welcomes this with the reply: “If it’s what you say, I love it, especially later in the summer.”

In a later email, Goldstone describes the Russian lawyer they are due to meet, Natalia Veselnitskaya, as a “Russian government attorney”.

Trump Jr agrees, adding that he would probably be accompanied by “Paul Manafort (campaign boss)” and “my brother-in-law,” Jared Kushner, husband of Trump’s daughter Ivanka and now a senior White House adviser.

The formatting of the emails suggests that Trump Jr forwarded the whole chain to Manafort and Kushner before the meeting the three attended with Veselnitskaya at Trump Tower in New York on 9 June.

On Sunday, Trump Jr had said he had asked Manafort and Kushner to attend but not told them what the meeting was about. An associate of Manafort said on Tuesday that the former campaign chairman claims not to have read to the bottom of the chain of emails forwarded to him and Kushner by Trump Jr about the meeting. Jamie Gorelick, an attorney for Jared Kushner, did not respond to questions about whether Kushner read the emails and why he attended the meeting.

Critics seized on the new disclosures to question why three of Trump’s closest advisers were willing to accept such a meeting instead of alerting authorities to interference by a foreign adversary. Special counsel Robert Mueller and the House and Senate intelligence committees are investigating Russian meddling in the election, thought to include stealing Democratic National Committee emails and the use of social-media bots to spread fake news about Clinton.

Trump spokeswoman Sarah Huckabee Sanders read a short statement from the president to reporters at the regular White House press briefing. “My son is a high-quality person and I applaud his transparency.”

She then refused to answer several questions on the matter, saying they must be directed to Trump Jr’s legal counsel and outside counsel.

Asked about the president’s reaction to the unfolding drama, Sanders replied: “I think the president is, I would say, frustrated with the process, the fact this continues to be an issue and he would love for us to be focused on issues like the economy, healthcare, tax reform, infrastructure.”

‘These emails are explosive’

Clinton’s running mate Tim Kaine, a senator from Virginia and member of the foreign relations committee, told MSNBC: “These emails are explosive. This should have set off alarm bells and red lights, and yet what it seemed to do is activate their salivatory glands. This is just wheelbarrows of new evidence for the special counsel and the Senate intelligence committee.”

Trump Jr released the email chain on Tuesday apparently to pre-empt its publication by the New York Times, which, this weekend, first broke the news of his meeting with Veselnitskaya in June last year. Veselnitskaya had promised compromising information about Clinton but apparently failed to deliver.

In a statement posted to Twitter, Trump Jr explained: “To everyone, in order to be totally transparent, I am releasing the entire email chain of my emails with Rob Goldstone about the meeting on June 9, 2016. To put this in context, this occurred before the current Russian fever was in vogue.”

There is no such position as crown prosecutor of Russia, but the most likely candidate would be the long-serving prosecutor general, Yuri Chaika.

Chaika, a long-standing member of Vladimir Putin’s elite, was justice minister for several years before being made prosecutor general in 2006, a post he has held ever…