Senate Democrats and Republicans agreed Tuesday to work together to keep protections for young illegal immigrants under DACA, in their first hearing since President Trump ended the Obama-era immigration policy -- but the partisan divide remained on full display.

Republicans called for increased border security while Democrats focused on the estimated 700,000 “dreamers” who would benefit from crafting a legislative alternative to the 2012 Deferred Action for Childhood Arrivals.

“We all have empathy for these young people, who came to this country through no fault of their own. And, for many of them, it is the only country they know,” Iowa Sen. Chuck Grassley, chairman of the Senate Judiciary Committee, said in his opening statement.

However, he followed up with demands that any new legislation “first and foremost” include “robust border security.”

“And by that, I don’t mean a wall,” Grassley said. “Tactical infrastructure like fencing is a part of the answer, but border security is more than that. Border security is an all-of-the-above approach and includes fencing, technology, funding for more law enforcement personnel and equipment.”

Trump announced in early September that the administration would end former President Barack Obama’s DACA executive action that essentially allows law-abiding illegal immigrants brought into the U.S. by their parents to live and work in the country without fear of deportation.

The administration argued federal courts were ready to strike down DACA as unconstitutional, which would put the dreamers in peril.

Trump gave Congress six months to find a legislative alternative, then struck a framework deal with House Democratic leader Nancy Pelosi, California, and Senate Democratic leader Chuck Schumer, New York, that could allow the dreamers to stay with an eventual path toward citizenship.

“If Republicans continue to insist on measures outside of the Dream Act and sensible border security that excludes the wall, they’re going to risk ruining a bipartisan agreement,” Schumer, who is not a member of the Judiciary committee, said after the hearing Tuesday.

At the hearing, California Sen. Dianne Feinstein, the committee’s top Democrat, continued her party’s efforts to highlight successful dreamers, in negotiating a legislative solution.

“They have become a part of America’s society. And efforts to expel them, I believe, would be unconscionable,” Feinstein said in opening remarks in which she also introduced Denisse Rojas, a dreamer and medical student at Mount Sinai in New York who would later testify before the committee.

“I am so proud of her,” Feinstein said. “The last … months must have been a rollercoaster of fear and uncertainty for young Miss Rojas and the rest of those young people.”

If Congress fails to act by March, dreamers’ work permits will begin to expire and they will become subject to deportation.

The hearing also included testimony on the issue from top officials from the Justice Department, Homeland Security Department and U.S. Citizenship and Immigration Services.

"They are a benefit to this country … They are a valuable contribution to our society," Michael Dougherty, an assistant Homeland Security secretary, testified as dozens of dreamers wearing orange shirts watched from the audience.

Dougherty; James McCament, ICE’s acting director; and Chad Readler, Justice’s acting assistant attorney general, all said they are eager to provide Congress with technical guidance on crafting legislation but declined several requests by senators to make suggestions.

Fox News' Joseph Weber and The Associated Press contributed to this report.