Obama addresses nation before 2012 presidential campaign heats up

Barack Obama set key themes for the upcoming presidential election as he delivered his third State of the Union address Tuesday night.

He called for an overhaul of the U.S. tax system, saying that America's wealthiest citizens need to pay their fair share in a tough economy burdened with debt.

Some billionaires, including Warren Buffet, have argued for tax increases.

Buffet has pointed out that he pays a lower rate than his secretary, Debbie Bosanek. And surely enough, Bosanek was there for the speech.

Republicans were critiquing Obama's stance on taxes before he took the stand.

The US will also work on linking clean energy to homes and the Navy.

"We will make one of the largest commitments to clean energy in history -– with the Navy purchasing enough capacity to power a quarter of a million homes a year," said Obama.

Obama mentioned his commitment to preventing Iran from obtaining any nuclear weapons and emphasized strong ties to Israel, Asia and Europe.