WASHINGTON (Reuters) - Months of bipartisan negotiations in the U.S. Senate over the fate of young, undocumented immigrants known as ‘Dreamers’ turned angry on Friday, with the lead Democratic negotiator blasting the White House for making “hardline anti-immigrant” demands.

'Dreamers' hug as they meet with relatives during the 'Keep Our Dream Alive' binational meeting at a new section of the border wall on the U.S.-Mexico border in Sunland Park, U.S., opposite the Mexican city of Ciudad Juarez, Mexico, December 10, 2017. Picture taken from the U.S side of the U.S.-Mexico border. REUTERS/Jose Luis Gonzalez

President Donald Trump in September ordered that an Obama-era program that prevented young immigrants from being deported should end in six months. The program is known as Deferred Action for Childhood Arrivals, or DACA.

Saving the Dreamers from deportation is a high priority for Democrats, but Republican and Democratic lawmakers have struggled to reach a bipartisan deal.

Senator Dick Durbin, the No. 2 Senate Democrat, said the White House on Friday had submitted a list of demands it wanted in order to agree a deal that were simply a repeat of a document it sent to Congress in early October. Democratic leaders rejected those demands at the time.

Further inflaming the negotiations, Durbin said, was an added White House demand for $18 billion to fund the construction of a wall along the southwestern border with Mexico, despite staunch Democratic opposition.

On Saturday, congressional Republican leaders are due to huddle with Trump at Camp David, the presidential mountain retreat, to discuss 2018 legislative priorities.

Republican and Democratic leaders are also scheduled to meet with Trump at the White House on Tuesday to talk about immigration legislation.

Durbin said the latest White House move, coming as Congress also struggles to pass a bill by Jan. 19 to fund the government through September, could push federal agencies closer to a shutdown.

Earlier, some congressional Republicans downplayed the likelihood of a deal with Democrats on legislation to protect the Dreamers - some 700,000 young immigrants who were brought to the United States as children.

Republican Senator John Cornyn accused Democrats in a tweet of trying to force a deal on Dreamers by doing a “slow walk” on efforts to approve critical disaster aid and defense spending.

Two other Republicans late on Thursday said the sides remained far apart. “Our discussions on border security and enforcement with Democrats are much further apart, and that is key to getting a bipartisan deal on DACA,” senators Thom Tillis and James Lankford said in a statement.

On Oct. 8, the White House released a list of immigration “principles” Trump wanted in return for giving Dreamers legislative protection from deportation.

Besides the border wall, it included the hiring of 10,000 more Immigration and Customs Enforcement agents and 300 federal prosecutors.

Immigration advocacy groups fear the hiring expansion would be part of an attempt to round up the adult relatives of Dreamers to ship them to their native countries.

Resubmitting the demands that were dismissed by Democrats three months ago, Durbin said, was “outrageous.” But he added that bipartisan negotiations continue among senators.

Democrats have said they are open to tying DACA to additional funding for border security technology. But they oppose Trump’s wall, which government estimates have said could cost over $21 billion.

Republican lawmakers met with Trump at the White House on Thursday and initially emerged saying they were optimistic that they could find a legislative fix for DACA.

The struggle over the Dreamers carries political weight for both parties heading into the November 2018 midterm congressional elections. Most of the Dreamers came from Mexico and Hispanics tend to vote for Democrats.

Cornyn, in an interview on Fox News on Friday, said Trump would demand that an immigration deal address the visa lottery system and chain migration that unites family members.

“Those are things that he’s insisted upon,” and Democrats would have to embrace them along with border security, said Cornyn.