For years, Russia has been anything but a willing partner of the United States. Relations became strained well before the election-related cyberattacks began nearly a year and a half ago, despite the Obama administration’s early effort to reset relations.

After Russia’s intrusion into Ukraine and its annexation of Crimea in 2014, the United States and its allies levied broad sanctions against the Russian economy and blacklisted dozens of its citizens, including some close to the Russian president, Vladimir V. Putin.

President Obama added to those measures last month in retaliation for the hacking, expelling 35 suspected Russian intelligence operatives from the United States and imposing sanctions on two Russian intelligence services. Russia and the United States have also often been at odds over Moscow’s involvement in the war in Syria.

Senior intelligence officials briefed Mr. Trump on their findings on Russian election interference on Friday, before releasing a declassified report that concluded that Mr. Putin had “ordered” a sprawling campaign intended to denigrate Hillary Clinton and aid Mr. Trump.