WASHINGTON - President Barack Obama says Mitt Romney has locked himself into "extreme positions" on economic and social issues and would impose them if elected.

Obama gave an interview to The Associated Press ahead of the GOP convention that starts Monday. Obama tries to discredit his Republican rival, saying Romney lacks serious ideas, refuses to "own up" to the responsibilities of the office he seeks, and deals in factually dishonest arguments that could haunt him in debates.

Obama says Romney's plans would worsen life for the middle class and offer no prospects for those trying to climb into it.

The president says in a second term, he would be willing to compromise with Republicans who are tired of what he calls one of the least productive Congresses in American history.