US President Barack Obama stopped short of pinning on Russia the hacking of Democratic Party computers, but said Tuesday it would be just the latest in a "long list of issues" between Washington and Moscow.
The FBI is still investigating the hacking incidents targeting the Democratic National Committee and other party offices, and Obama said at a press conference that "there are a lot of countries out there that are trying to hack into our stuff."
"If in fact Russia engaged in this activity, it's just one on a long list of issues that me and Mr Putin talk about, and that I have got a real problem with," Obama said, noting the hacking alone would not substantially change the already complicated relationship with Moscow.
He said the United States has provisions to go after state-sponsored hackers and called on other governments not to engage in cyber attacks.
The website WikiLeaks published some 20,000 Democratic Party emails that exposed apparent favouritism for Hillary Clinton over rival Bernie Sanders by party officials during its presidential primaries. The revelations led to the resignation of party chairwoman Debbie Wasserman Schultz.
On Thursday, three more top Democratic Party operatives resigned in the wake of the email leaks. The party's chief executive Amy Dacey, communications director Luis Miranda and chief financial officer Brad Marshall all left their positions.
The Clinton campaign and outside computer analysts have blamed the hacking on Russia, but the US government has yet to weigh in publicly. Moscow has denied the allegation.
Republican Donald Trump drew Democratic criticism when he suggested the Russians should use their hacking skills to recover missing emails from a private email server, used by Clinton when she was secretary of state.