The FBI reportedly started investigating whether Trump was a Russian asset after he fired Comey

Andrew Harrer-Pool/Getty Images

President Donald Trump, left, shakes hands with James Comey, director of the Federal Bureau of Investigation, during an Inaugural Law Enforcement Officers and First Responders Reception in the Blue Room of the White House on January 22, 2017 in Washington, D.C.

• The FBI reportedly grew so concerned about some of President Donald Trump's early actions and public statements in office - including his move to fire director James Comey - the agency opened a counterintelligence inquiry on the matter.
• According to a New York Times report published Friday night, Trump's actions and behaviors had national-security implications, including whether Trump was intentionally or unintentionally undermining US interests at the behest of Russia.
• The development adds a new wrinkle to the broader Russia investigation in which US law-enforcement officials are looking into the extent of Russia's wide-ranging effort to influence the 2016 presidential election.

After President Donald Trump fired FBI director James Comey in May 2017, the bureau became so concerned about his actions that it opened a counterintelligence investigation into whether Trump was intentionally or unintentionally working for the Russians, according to a bombshell New York Times report.

FBI agents had already been suspicious of Trump's ties to Russia since his 2016 presidential campaign but, according to The Times' sources, there was some concerns within the agency about how to approach the situation given its sensitivity.

Trump's move to fire Comey also triggered a criminal obstruction-of-justice inquiry, a matter that has only escalated since the special counsel Robert Mueller was appointed to oversee the Russia probe in May 2017.

Read more: Here are all the key developments you might have missed in Russia news this week

Pablo Martinez Monsivais/AP Photo

US President Donald Trump takes his seat as he attends the multilateral meeting of the North Atlantic Council in Brussels, Belgium.

Trump's interview with NBC News' Lester Holt in May 2017, in which the president confessed he had asked Comey whether he was under investigation for his alleged links to Russia, raised alarms at the FBI and fueled the counterintelligence inquiry, according to The Times.

Trump's other public statements, including encouraging Russia to hack his Democratic opponent Hillary Clinton's emails, also attracted scrutiny from the FBI, the newspaper's sources reportedly said.

It is unclear whether Mueller is still looking into the counterintelligence aspect of the investigation, according to The Times.

Trump attorney Rudy Giuliani, who the newspaper said had no knowledge of the FBI inquiry, appeared to be unfazed: "The fact that it goes back a year and a half and nothing came of it that showed a breach of national security means they found nothing," he said to The Times.

Trump has repeatedly denied any wrongdoing and frequently rails against Mueller and the Russia investigation.