MOORE, Oklahoma (AFP) - President Barack Obama traveled to Oklahoma to view devastation from last week's monster tornado that killed 24 people, as the governor sought federal aid for thousands left destitute by the disaster.

Obama departed Washington on Sunday to the tornado-ravaged state, where he was to meet with survivors and first responders, and will survey the mountains of debris strewn across this battered state.

Speaking to CNN on Sunday, Governor Mary Fallin said she is seeking help streamlining assistance to her battered state from the Federal Emergency Management Agency (FEMA) following the powerful twister, which ripped through this Oklahoma suburb almost one week ago, injuring 377 people.

"What I need is the ability to get through red tape, the ability to get the FEMA funds in here quickly and to get the services that our citizens need to help them recover through this terrible disaster," she said, standing before a mountain of twisted metal, brick and wood.

"The debris, as you can see behind me, is huge. It's not just a couple houses with roofs off," she said.

"This is a massive debris field. It's not just a couple blocks. It's miles. It's 27 kilometers long, almost 2.4 kilometers wide."

The tornado was one of the most powerful in years, damaging or destroying 1,200 homes and affecting an estimated 33,000 people, according to a recent update from officials.

Initial damages have been estimated at around US$2 billion (S$2.53 billion) .

"We had five schools that were hit. So a lot of areas that have been destroyed and a lot of people need to get back on their feet," Fallin said.

The town of Moore suffered a similarly powerful tornado in 1999 that killed 41 and another in 2003.

A public memorial was to be held later Sunday in the tight-knit community, where Obama was also was expected to scheduled to comfort survivors and take stock of the destruction and clean-up.

But Governor Fallin emphasized the community was also rallying together to move on.

"We're resilient. There's already a big path of debris that's been moved around. People are gathering their stuff," she said.

"It's been truly remarkable to see how our people have responded and how strong they are." Part of that process has included taking up the threads of ordinary life, including holding scheduled graduations.

Three area high schools held ceremonies Saturday back-to-back at a local convention center.

"We gather today to celebrate under unique and trying circumstances," Terry Tamage, a teacher at Westmoore High School, told the crowd. "We are acutely aware of the events of this week." He told the crowd to "celebrate the class of 2013 in a way that is joyful but respectful of our seniors and our community." Free caps and gowns were distributed to students who had lost their homes in the tornado, but at least one student didn't need one.

Zach Joyner, 18, a graduate of Southmoore High, told the Los Angeles Times he grabbed his blue cap and gown before rushing into a storm shelter before the house was destroyed.

"It's important to me," he said of the traditional graduation garb. "I thought, 'I cannot take a chance on this.'" The United States experiences three out of four tornadoes in the world, but the one that hit Monday was an unusually powerful EF-5 on the Enhanced Fujita scale - the highest possible level - and touched down with little advance notice.

It followed roughly the same track as the 1999 twister, yet very few homes in Oklahoma - and neither of the stricken schools - had purpose-built storm shelters.