WATFORD, ENGLAND - President Donald Trump on Wednesday dismissed the significance of repeated contacts between his personal attorney Rudy Giuliani and phone numbers linked to the White House and its budget office - contacts that were revealed in the House intelligence committee's impeachment report.

"So somebody said he made a phone call into the White House. What difference does that make?" Trump commented during his meeting with Italian Prime Minister Giuseppe Conte on the sidelines of a NATO meeting Wednesday in London.

"Is that supposed to be a big deal?'" he added. "I don't think so."

The 300-page House report is serving as the basis for the House Judiciary Committee's efforts beginning Wednesday to formally move forward on drafting articles of impeachment against Trump.

The report includes phone records obtained from AT&T and Verizon, showing extensive contact between Giuliani and the White House. On April 24, Giuliani had three calls with a number associated with the Office of Management and Budget, and eight calls with a White House number, the documents show.

But Trump on Wednesday insisted he knew nothing about the calls. He defended Giuliani as a "very good lawyer," a "great crime fighter" and "the best mayor in the history of New York City."

"Rudy is a great gentleman and they're after him only because he's done such a good job. He was very effective against Mueller and the Mueller hoax," Trump said, referring to former special counsel Robert Mueller's investigation into Russian meddling in the 2016 election.

He also encouraged reporters to ask Giuliani about the calls, but claimed they are "no big deal."

Giuliani has long pushed the debunked conspiracy theory that Ukraine interfered in the 2016 election and worked to push Ukrainian officials to investigate the son of Trump's potential Democratic challenger, Joe Biden. Hunter Biden was on the board of a Ukrainian energy company.