WASHINGTON - Donald Trump Jr., the eldest son of US President Donald Trump, who was embroiled in controversy for meeting a Russian lawyer, would be called on to testify before Congress, said the US Senate Judiciary Committee Thursday.

Republican Senator Chuck Grassley said he intended to send a letter to Trump Jr., summoning him for questioning, US media outlet CNN said, and Trump Jr. may be called upon as early as next week.

Anyone asked to testify before the Senate should comply, House Speaker Paul Ryan said Thursday.

Trump Jr. on Tuesday released full email records leading up to a meeting with a Russian lawyer with suspected ties to the Russian government last June, fueling speculation that Trump's campaign had colluded with the Russian government during last year's presidential campaign.

According to the emails, Trump Jr. agreed to the meeting after being told by a publicist that the Russian lawyer, Natalia Veselnitskaya, possessed damaging information on Trump's opponent Hillary Clinton.

In a recent interview, Veselnitskaya denied having discussed Hillary-related issues with Trump Jr. during the meeting. She also denied ties to the Russian government.