US Republicans win control of the lower house of Congress in key elections, setting up a new challenge to President Barack Obama's agenda.

Leading Republican John Boehner urges Barack Obama to change course and vows to reverse his healthcare reforms, after the president's Democrats suffer a severe setback in mid-term elections.

US President Barack Obama says he believes US citizens are feeling frustrated with the pace of economic recovery, after his Democratic Party suffers a disastrous election night.