SENIOR US Democrats have pledged to investigate a report that Donald Trump directed his personal lawyer to lie to Congress about negotiations over a real estate project in Moscow during the 2016 presidential election.

House Intelligence Committee chairman Adam Schiff said: “We will do what’s necessary to find out if it’s true.” He said the allegation that the president directed Michael Cohen to lie in his 2017 testimony to Congress was “among the most serious to date”.

The chairman of the House Judiciary Committee, Jerrold Nadler of New York, said directing a subordinate to lie to Congress is a federal crime. “The @HouseJudiciary Committee’s job is to get to the bottom of it, and we will do that work,” he tweeted. The report by BuzzFeed News said that Trump directed Cohen to lie to Congress and that Cohen regularly briefed Trump and his family on the “Trump Tower” project – even as Trump said he had no business dealings with Russia. Trump tweeted that Cohen was: “Lying to reduce his jail time!”

Cohen pleaded guilty in November to lying to Congress in 2017 to cover up that he was negotiating the real estate deal in Moscow on Trump’s behalf. Cohen was recently sentenced to three years in prison after pleading guilty to tax crimes, bank fraud and campaign violations.

Meanwhile, House Speaker Nancy Pelosi cancelled plans to travel on a commercial airline to visit US troops in Afghanistan after accusing Trump of causing a security risk by talking about the trip. It was the latest twist in the game of brinkmanship between the pair playing out against the stalled negotiations over how to end the partial government shutdown.

Earlier in the week, Trump cancelled the military plane Pelosi and a congressional delegation to Afghanistan were to use on the previously undisclosed visit. He suggested she travel by commercial plane instead. Spokesman Drew Hammill said Pelosi and accompanying lawmakers were prepared to do that but cancelled after the State Department warned publicity over the visit had “significantly increased the danger to the delegation and to the troops, security, and other officials supporting the trip”.

Yesterday, it was also revealed Trump was meeting a North Korean envoy in the Oval Office to discuss efforts to get the country to give up its nuclear programme. White House press secretary Sarah Huckabee Sanders said the meeting with Kim Yong Chol was to discuss relations between the two countries and continued progress on “North Korea’s final, fully verified denuclearisation”.

The former North Korea spy chief earlier had talks with Secretary of State Mike Pompeo at a Washington hotel. A planned meeting in November had been abruptly called off.