NEW YORK -- President Barack Obama ventured onto the hallowed ground of the World Trade Center site Thursday, getting a firsthand look at the skyscraper being built to replace the twin towers destroyed in the Sept. 11, 2001, terror attacks.

"This is what the American spirit is all about," Obama said.

The president toured the 22nd floor of One World Trade Center in lower Manhattan, walking along the unfinished cement floor and stopping at easels set up with renderings of what the completed tower will look like.

Joined by first lady Michelle Obama, the president later came down to the base of the building and signed a large white beam – affixed with the words "One World Trade Center" painted in blue – that will be used in the construction. Obama inscribed on the beam, "We remember we rebuild we come back stronger!" followed by his signature.

For Obama, the visit offered an increasingly rare election year break from fundraising and other campaign-related events. But it also provided a president running for re-election with a potent picture of American resilience.

Obama told about 50 workers gathered near the beam that the building was an "incredible structure," and that it represented the American spirit. He was joined by a bipartisan cast of local officials, including Gov. Andrew Cuomo, Mayor Michael Bloomberg and New Jersey Gov. Chris Christie, a top surrogate for Republican presidential candidate Mitt Romney.

The skyscraper is expected to be completed in early 2014. As of Wednesday, steel had been erected up to the 104th floor, and workers had begun installing marble finishing on the ground floor.

Obama last visited the World Trade Center site in September for the 10th anniversary of the attacks.

The president was attending two fundraisers in New York, including one at the home of actress Sarah Jessica Parker. It capped a day that included a campaign speech in Cleveland, in which the president sought to draw a sharp distinction with Romney on the economy, saying the election would give voters a chance to break a "stalemate" over the direction of the nation's economy.

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  • Michelle obama

    First lady Michelle Obama greets workers during a visit to the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)

  • Barack Obama

    President Barack Obama greets workers at the Port Authority of New York and New Jersey's World Trade Center site, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)

  • Barack Obama, Chris Christie Michael Bloomberg, Andrew Cuomo, Michelle Obama,

    President Barack Obama and first lady Michelle Obama, second from left, visit the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress, Thursday, June 14, 2012, in New York. With him on the tour are New Jersey Gov. Chris Christie, left, New York Mayor Michael Bloomberg, right, and New York Gov. Andrew Cuomo, second from left. (AP Photo/Carolyn Kaster)

  • Barack Obama, Chris Christie Michael Bloomberg, Andrew Cuomo

    President Barack Obama visits the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress Thursday, June 14, 2012, in New York. With him on the tour are New Jersey Gov. Chris Christie, New York Mayor Michael Bloomberg, and New York Gov. Andrew Cuomo. (AP Photo/Carolyn Kaster)

  • Barack Obama, Michelle obama, Andrew Cuomo, Chris Christie

    President Barack Obama speaks as he gathers with New York Gov. Andrew Cuomo, left, first lady Michelle Obama, second from right, and New Jersey Gov. Chris Christie, right, to sign a white steal beam as they visit the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)

  • Barack Obama, Michelle obama

    President Barack Obama and First Lady Michelle Obama's signatures are seen on a white steal beam at the the Port Authority of New York and New Jersey's World Trade Center site, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)

  • Barack Obama, Andrew Cuomo, Chris Christie

    President Barack Obama, right, New York Gov. Andrew Cuomo, center, and New Jersey Gov. Chris Christie, visit the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)

  • A motorcade passes the National September 11 Memorial Thursday, June 14, 2012, in New York. President Barack Obama was touring the 22nd floor of One World Trade Center in lower Manhattan, walking along the unfinished cement floor and stopping at easels set up with renderings of what the completed tower will look like. (AP Photo/Frank Franklin II)

  • Barack Obama, Michelle obama

    President Barack Obama shakes hands with workers as he visits the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)

  • Barack Obama, Michelle obama

    President Barack Obama and first lady Michelle Obama look out over the 9/11 Memorial as they visit the Port Authority of New York and New Jersey's World Trade Center site for a briefing on construction progress, Thursday, June 14, 2012, in New York. (AP Photo/Carolyn Kaster)