BRUSSELS (Reuters) - U.S. Defense Secretary Jim Mattis on Tuesday played down any impact that White House national security adviser Michael Flynn’s resignation might have on Mattis’ debut trip this week to Europe to meet NATO allies. “Frankly, this has no impact. Obviously, I haven’t changed what I’m heading there for. It doesn’t change my message at all,” Mattis told reporters shortly before landing in Brussels, as he praised the NATO alliance but stressing its need to adapt to the challenges posed by Russia. “And who’s on the president’s staff is who I will work with,” he said. Flynn resigned late on Monday after revelations that he had discussed U.S. sanctions on Russia with the Russian ambassador to the United States before Trump took office and had misled Vice President Mike Pence about the conversations. Flynn’s resignation occurred hours after it was reported that the Justice Department had warned the White House weeks ago that Flynn could be vulnerable to blackmail for contacts with Russian ambassador Sergei Kislyak before Trump took power on Jan. 20. Mattis has taken a dimmer view of the prospects of partnership with Moscow than Flynn did during the presidential campaign or Trump has since taking office, while not ruling out areas where U.S. and Russian interests might align. Speaking to reporters on Tuesday, Mattis said the North Atlantic Treaty Organization needed to adapt to the challenges posed by Russia after 2014, when Russia’s annexation of Ukraine’s Crimea peninsula upended the alliance’s assumptions about cooperation with Moscow. “2014 was a watershed year. It was a year when many of our hopes for some kind of partnership with Russia were shown to be unavailing,” Mattis said, extolling NATO as “the most successful military alliance in history.” “We’ve got to adapt and make certain that the trans-Atlantic bond remains strong,” he said. In his January Senate confirmation hearing, Mattis accused Russia of trying to break the NATO alliance. [nL1N1F218B] Flynn, in contrast, frequently raised eyebrows among Washington’s foreign policy establishment for trying to persuade Trump to warm up U.S. relations with Russia. One U.S. official said Flynn’s departure, coupled with Russia’s aggression in Ukraine and Syria and Republican congressional opposition to removing sanctions on Russia, removes Trump’s most ardent advocate of taking a softer line toward Russian President Vladimir Putin. Flynn’s leaving “may make a significant course change less likely, at least any time soon,” the official said. [nL1N1FY1L9] Another official said Flynn’s departure might strengthen the hands of some Cabinet secretaries, including Mattis and Secretary of State Rex Tillerson. 
U.S. defense chief: White House shakeup will not affect Europe debut