U.S. Secretary of State Hillary Clinton says the U.N.’s adoption of sanctions on North Korea was due, in part, to the Obama administration's engagement policy last year.

Clinton said during an appearance on CNN's "State of the Union" that engagement has achieved a lot in the last year in regards to proliferation by Iran and North Korea.

She said the U.S. expressed its willingness to work with North Korea if it was serious about returning to the six-party talks and about denuclearizing in an irreversible way. But she said the North did not respond to this approach.

Clinton said that because the U.S. was willing to engage, it ended up getting a very strong sanctions regime against North Korea that China and Russia have signed on to and that is being enforced around the world.