Obama to world: 'we mean what we say'

President Barack Obama aimed to strengthen the resolve of the nation on Thursday during the visit to the World Trade Center on Thursday as he spoke firefighters and victims' families of the Sept 11, 2011 attacks.

Obama made his first stop in the visit to a fire in Midtown Manhattan with the crew of Engine 54, Ladder 4, battlion 9, which saw 15 of its own die in the attacks which brought down the Twin Towers.

He said there that the killing of bin Laden, sent a message around the world, but also sent a message here back home, that when we say we will never forget, we mean what we say.

It didn't matter who was in charge, we were going to make sure that the perpetrators of that horrible act -- that they received justice, Obama said

Obama did not make any public statements when he laid a wreath at a ceremony on the World Trade Center site, where he was accompanied by police officers, firefighers and victims' families.

He also met separately with police at a precinct in Tribeca and members of victims' families at the September 11th National Memorial preview site next to Ground Zero.

Crowds outside the firehouse chanted U-S-A, U-S-A, as Obama arrived to have lunch with firefighters, joined by former Mayor Rudy Giuliani and Fire Commissioner Salvatore Cassano.

The President said that the 9/11 attacks were the high-water mark of courage for the New York fire-department and that he was thankful for their services .

His visit marks the dramatic announcement that al-Qaeda leader Osama Bin Laden, was killed at his Pakistan compound on Sunday.

Obama said on Monday at ceremony honoring military service members that the world is safer; it is a better place because of the death of Osama bin Laden.

Today, we are reminded that, as a nation, there's nothing we can't do -- when we put our shoulders to the wheel, when we work together, when we remember the sense of unity that defines us as Americans, Obama said.

The president laid a wreath at 1:25 p.m in memory of the victims of the September 11 attack.