US President Barack Obama said on Tuesday if Russia had engaged in hacking Democratic Party organizations it would be an issue he would discuss with President Vladimir Putin, but it would not "wildly" alter the countries' relationship.

The United States already has "a lot of differences with Russia on a whole bunch of issues, but I think that we've been able to try to stay focused on those areas where we still have a common interest," Obama said at a news conference during a state visit with Singapore's Prime Minister Lee Hsien Loong.

Calling the relationship between the United States and Russia tough and difficult, Obama noted common concerns.