WASHINGTON - Both US President Barack Obama and Republican challenger Mitt Romney have been working hard over the weekend in preparation for their last presidential debate of this election cycle scheduled for Monday night, with fresh attacks being exchanged at each other before the final face-off.

The third and final debate between Obama and Romney is due to take place in Boca Raton, the US state of Florida, with its focus on foreign policy. Stakes are running high for the two candidates, as Romney's landslide victory in the Oct 3 presidential debate, the first of the kind, served as a boost to his support ratings while Obama's more aggressive performance in the second debate on Tuesday has been expected to hold back the waning momentum after the first one.

Obama has been hunkering down in Camp David since Friday till Monday morning to prep for the final showdown in a debate hall. Romney will also be preparing with aides in Florida during the weekend.

Both of them left their running mates as surrogates on the campaign trail towards battle grounds. Vice-President Joe Biden and his challenger Paul Ryan were due to show up in campaign events in Florida and Ohio, respectively, the two swing states key to the result of the Nov 6 Election.

The two campaign teams also traded assaults over each other's agenda in preparation for Monday's presidential debate.

"The Obama campaign has become the incredible shrinking campaign," Romney told the audience at a rally in Daytona Beach, Florida, Friday night. The former Massachusetts governor also accused Obama's re-election campaign with "no agenda for the future, no agenda for America, no agenda for the second term".

The Obama campaign on Friday also coined a term "Romnesia" to describe Romney's shifting positions.  The term has gone viral on the Internet.

A latest Gallup poll released on Friday showed more Americans believed Obama did a better job than Romney during the second presidential debate, by 51 percent to 38 percent. The rating showed a sharp reversal from the first presidential debate for which Romney was regarded as a landslide winner by 72 percent.