* Senate passes disaster aid, fiscal package; sends to House
* Trump talks to Democrats on fate of "Dreamer" immigrants (Updates with Trump comments on debt ceiling, Senate approval of bill)
WASHINGTON, Sept 7 (Reuters) - President Donald Trump embraced the idea on Thursday of ending the need for periodic raises of the ceiling on U.S. debt by Congress, again siding with Democrats a day after stunning fellow Republicans by striking a deal with the opposition party on the debt limit and federal spending.
Trump also turned to Democratic congressional leaders on Thursday in an effort to resolve another pressing matter, the fate of the 800,000 so-called Dreamers, young adults brought illegally into the United States as children.
The Senate approved $15.25 billion in aid for areas affected by Hurricane Harvey and other natural disasters, along with measures in the deal Trump reached with Democrats that would fund the federal government and raise its borrowing limit through Dec. 8.
The bill now goes go to the House of Representatives for final congressional approval. But the measure faced stiff opposition from House conservatives who traditionally favor strict curbs on federal spending.
The leadership of the largest group of House Republican conservatives came out against the deal on Thursday, saying it meant more federal spending without fiscal reforms.
After blindsiding Republican leaders with that agreement, Trump called top House Democrat Nancy Pelosi and top Senate Democrat Chuck Schumer on Thursday morning, along with the Republican congressional leaders with whom he has had a tense relationship.
Trump embraced the idea of eliminating the statutory cap on the U.S. Treasury Department's authority to borrow to keep funding federal deficits and meet debt obligations. Over the years, some conservative Republicans have opposed increasing the debt ceiling without significant cuts in federal spending. That resistance has caused jitters in financial markets over the prospect of an unprecedented U.S. government default on debt.
"For many years, people have been talking about getting rid of debt ceiling altogether, and there are a lot of good reasons to do that," Trump told reporters. "It complicates things, it's really not necessary."
"So certainly that's something that will be discussed," Trump added, noting that it was talked about during his White House meeting on Wednesday with Pelosi, Schumer, House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell.
According to one congressional aide, Trump and Democratic leaders did not get into details over whether they would seek legislation repealing the Treasury's borrowing limit or revert to a past practice of automatic debt limit increases when annual budget blueprints are approved by Congress.
Ryan said on Thursday he opposes any effort to do away with the role Congress has in approving debt limit increases, citing the powers given to Congress under the U.S. Constitution.
"The president encouraged congressional leaders to find a more permanent solution to the debt ceiling so the vote is not so frequently politicized," White House spokeswoman Sarah Sanders said.
DREAMERS AND DEMOCRATS
On the issue of the so-called Dreamers, Pelosi said Trump made clear he wants Congress to act.
On Tuesday, the president rescinded a program created by his Democratic predecessor Barack Obama, the Deferred Action for Childhood Arrivals, that protected them from deportation and provided them work permits. Trump gave Congress six months to work on an alternative by delaying implementation until March.
Democrats want Congress to pass legislation addressing the Dreamers without other issues attached, but Pelosi did not rule out including border security measures that Trump and Ryan want included.
"I am praying that the president really cares about the Dreamers, or knows that he should care about the Dreamers, and that we're going to pass this bill. And we want to do it as soon as possible to strike while the iron is hot, because public opinion is so much in favor," Pelosi told reporters.
Pelosi added that Trump "probably wants some border enforcement and we have a responsibility to secure our borders," but said that does not include his planned wall along the U.S.-Mexico border, which is opposed by many Democrats.
Pelosi said she told Trump the Dreamers needed his assurance his action did not set up a six-month period of roundup for deportation. Trump subsequently wrote on Twitter, "For all of those (DACA) that are concerned about your status during the 6 month period, you have nothing to worry about - No action!"
The House approved a $7.8 billion disaster relief measure on Wednesday to help rebuild Texas and Louisiana from the destruction of Hurricane Harvey.
Senate negotiators, eyeing urgent requests from Florida officials who are expecting heavy damage from Hurricane Irma, nearly doubled that sum, cobbling together a $15.2 billion emergency spending bill.
As well as addressing the debt limit, the Senate bill would continue current government funding, which otherwise would expire on Sept. 30 at the end of the fiscal year, until Dec. 8. This move would avoid a possible government shutdown as the next fiscal year starts on Oct. 1.
(Reporting by Richard Cowan and Amanda Becker; Additional reporting by Susan Cornwell and Doina Chiacu; Writing by Will Dunham; Editing by Frances Kerry)