Republicans from New York and New Jersey have pledged unconditional support for those devastated by Hurricane Harvey, despite lingering resentment.

Key points: Texas Senator Ted Cruz opposed Sandy relief fund in 2012

Texas Senator Ted Cruz opposed Sandy relief fund in 2012 Northern Republicans still pledged to come to the aid of "fellow Americans"

Northern Republicans still pledged to come to the aid of "fellow Americans" Harvey could be the most expensive natural disaster in US history

As historic floods wreaked havoc across the Gulf Coast, north-eastern Republicans recalled the days after Superstorm Sandy ravaged their region in 2012.

At the time, Texas' Republican politicians, led by Senator Ted Cruz, overwhelmingly opposed a disaster relief package they argued was packed with wasteful spending.

The debate delayed the passage of the Sandy relief package by several weeks.

Five years later, another powerful natural disaster has exposed lingering resentment that underscores regional divisions in a deeply divided Republican Party.

"It was cruel, it was vicious, and something that I'll never forget," Republican Peter King, from New York, said.

He said Texas Republicans held up the 2012 bill as part of "a political ploy against the north-east."

"Having said that," Mr King added, "I don't want the people of Texas to suffer."

Mr King's comments were representative of several New York and New Jersey Republicans who said they were still angry, but would not employ the tactics of their Texas colleagues as Congress awaits an expected Trump administration request for billions of dollars of assistance.

Sorry, this video has expired Texas Governor warns of "incredibly heavy rain" to come as Harvey floods Houston

It may take weeks or months to survey the damage, but early estimates suggest Harvey could be one of the most expensive natural disasters in US history.

"We're not going to hold it against those poor Texans who need our help, what their representatives tried to do to us back five years ago," said Republican Dan Donovan.

"This is an American crisis and we come to the aid of our fellow Americans."

Senator Cruz's office said it was too soon to say whether he could pledge unconditional support to a massive disaster assistance package.

In recent days, he has defended his opposition to a $US51 billion Sandy relief bill he said was filled with "pork".

"When regions face serious disasters causing extensive damage, the federal government has an obligation to assist with assets to address the emergency," Mr Cruz's spokeswoman Catherine Frazier said.

"Senator Cruz strongly supports this role of government, but emergency bills should not be used for non-emergency spending and that unfortunately is what made up nearly 70 per cent" of the Sandy relief bill.

The Congressional Budget Office found that the Sandy relief package was distributed relatively slowly, but virtually all of the funding was related to the storm or to prevent future disasters.

"I don't want to revisit who did or didn't vote for the legislation then," said Republican Leonard Lance.

"I think it's needed now, and I'll be voting for it when we return to Washington."

AP