Trump has denied all knowledge of the encounter.
A federal special counsel is leading a criminal investigation of Russian interference in the 2016 USA presidential election, and any possible cooperation with Trump's presidential campaign.
Emin Agalarov, an Azerbaijan-born pop star, found himself at the center of questions about the Trump campaign's potential ties to Russia when it became public previous year that his publicist, Rob Goldstone, had reached out to Donald Trump Jr. about meeting with a Russian lawyer for dirt on Hillary Clinton. Mueller has also agreed to allow Trump to answer some questions in writing.
"Glad to see the White House finally do something about election security - even if it's only a press conference".
When asked at the summit if he preferred a Trump victory in 2016, Putin responded: "Yes, I did". It could be a much different story under a new Democratic House if the midterms go against the GOP.
Since Mueller began to lead the probe in May 2017, he has indicted or secured guilty pleas from 32 people, including several former Trump campaign aides.
That sounded to numerous president's critics like an official order to a member of his Cabinet to stop Mueller's work - or Trump would find someone willing to. "There is now highly credibly evidence that the president of the United States is committing obstruction of justice in real time, right before our eyes".
Sen. Mark Warner of Virginia, the ranking Democrat on the Senate intelligence committee who has criticized Trump for not taking a stronger leadership role on election security, said he was heartened by the White House news conference. But Cohen is said to be willing to testify that he witnessed Donald Trump Jr., the president's eldest son who was at the Trump Tower meeting, tell his father about it in advance. "Now if only it was actually backed up by anything the President has said or done on Russian Federation", U.S. Senator Mark Warner, a Virginia Democrat, said in a tweet.
White House press secretary Sarah Huckabee Sanders, as is her want, tried to give the president wiggle room to protect him against self-incrimination.
In a further tweet, Trump suggested Manafort has been harshly mistreated.
From Mueller's point of view, it may not matter.
Richard Painter, who served as an ethics lawyer for President George W. Bush, said in a telephone interview Wednesday that he would read the tweet as instructing Sessions to put himself back in charge of the Russian Federation probe.
But this is a blatant lie, and we know Trump knows it's a lie.
Each time Trump communicates his desire to impede, end or decapitate (by firing Mueller or Deputy Attorney General Rod J. Rosenstein), he gives prosecutors one more piece of evidence to fit into the portrait they are painting of a besieged president trying to avoid embarrassing disclosures.
Roughly two hours after calling on Mr Sessions to end the probe, the president tweeted out a passionate defence of Mr Manafort.
Earlier on Thursday, key members of Trump's national security team had appeared in the White House briefing room to warn that Russian Federation was continuing its efforts to interfere in the U.S. political system, saying Trump had directed them to make countering election interference a top priority.