United States President-elect Donald Trump has rejected as “ridiculous” US intelligence reports that Russia intervened in the presidential election on his behalf through targeted hacking, putting him at odds with top lawmakers who vowed to investigate the findings.

He blamed Democrats for news reports on the intelligence findings and said he did not believe they came from the Central Intelligence Agency.

“I think it’s ridiculous. I think it’s just another excuse. I don’t believe it,” Trump said in an interview on “Fox News Sunday.”

Trump‘s reluctance to blame Russia for interfering in the US election has raised concerns among US officials who fear he will go soft on Moscow at a time when they are worried about its increasingly aggressive behaviour on cyber attacks and in Crimea, Ukraine and Syria.

A US intelligence official, speaking on condition of anonymity, harshly criticised Trump‘s rejection of the assessment that Russian hacking was intended to boost the president-elect’s prospects in the November 8 election.

“It’s concerning that intelligence on Russian actions related to the US election is being dismissed out of hand as false or politically partisan,” said the US intelligence official.

“The inclination to ignore such intelligence and impugn the integrity of US intelligence officials is contrary to all that is sacred to national security professionals who work day and night to protect this country.”

The unusually harsh comment underscored the unprecedented tensions that Trump has created with the intelligence community he will command even before he’s been sworn into office.

Two leading US Senate foreign policy voices from Trump‘s own party expressed alarm on Sunday about the possibility of Moscow tipping the scales in favor of an American presidential candidate and promised to begin investigating immediately.

The Obama White House, which has ordered intelligence agencies to review cyber attacks and foreign intervention in the 2016 election, has formally accused Russia of a campaign of cyber attacks against Democratic Party organizations ahead of the presidential election.

Russian officials, who have previously vehemently denied accusations of interference in the US election, were quiet.

In his search for a secretary of state, Trump, a New York real estate magnate, is strongly considering Exxon Mobil Corp Chief Executive Rex Tillerson, who has close ties with Moscow and has spoken out against US sanctions on Russia.

Republican Senator John McCain expressed concern about Tillerson’s close relationship withRussian leader Vladimir Putin. “That would color his approach to Vladimir Putin and the Russian threat,” he said on Sunday on CBS’ “Face the Nation.”

A number of US senators have expressed concerns about Tillerson, suggesting his nomination could run into trouble in the Senate.

Trump‘s pick as national security adviser, retired Army Lieutenant General Michael Flynn, has also raised eyebrows in military circles through appearances on Russia‘s government-run broadcaster RT, particularly at a gala last year attended by Putin.

But Trump‘s choices to lead the CIA and the Pentagon, US Representative Mike Pompeo and retired Marine General James Mattis, are more likely to take a harsher stance on Russia.

US intelligence agencies have told Congress and President Barack Obama’s administration that Russia has grown increasingly aggressive in Syria and Ukraine and has stepped up activities in cyberspace, including meddling, sometimes covertly, in European and U.S. elections.

A senior US intelligence official told Reuters that intelligence agencies had concluded with “high confidence” that not only did their Russian counterparts direct the hacking of Democratic Party organizations and leaders, but did so to undermine Democratic candidate Hillary Clinton.

– Reuters