Sen. Lindsey Graham said Thursday he has given up his attempt to negotiate an end the partial government shutdown and said he has "never been more depressed" after trying to find an answer.

Graham had been pushing the White House, Senate Republicans, and Senate Democrats to find a legislative agreement on border security so President Trump wouldn't have to declare a national emergency to access money to build a border wall. But Graham's effort came crashing down Thursday as momentum halted.

"I just don't see a pathway," Graham told reporters. "I'm done. I don't know who to talk to, and I don't know what else to do."

"I don't see a pathway forward. The president's not going to back down," he said. "The Democrats are apparently not going to negotiate until the government is open, and if you even open the government, the House isn't going to negotiate about funding for the wall."

The lack of any legislative solution had some observers guessing that President Trump would soon declare a national emergency in order to gain access to federal money to build parts of the border wall without waiting for approval from Congress.

[Nancy Pelosi: Trump will anger GOP if he skirts Congress on wall]

Graham had held meetings with select Senate Republicans on Wednesday in a last-minute push to strike a deal to reopen the government, but none of the ideas took hold.

"I have never been more depressed about moving forward than right now. I just don't see a pathway forward. Somebody's got to like get some energy to fix this," Graham said. "I've run out of ideas."

"I felt really good about it until like an hour ago," he said. "I don't know. I'm trying to figure it out. It just kind of went away."

Graham added that he was going to go meet with Sen. Ron Johnson, R-Wis., before going to the gym.

The South Carolina senator had floated a possible compromise between the White House and Senate Democrats involving a deal to fund the president's call for a border wall in exchange for a solution on Dreamers and those who are given temporary protected status.