Washington CNN  — 

A Republican senator warned on Sunday that if President Donald Trump declares a national emergency on the southern border in order to fund the construction of a border wall, the move is “going to go to court and the wall won’t get built.”

“I would hate to see it. Using that act, it would be – in this instance, it would be a far larger act than has ever occurred in the past, so I’d prefer not. Primarily because if we do that, it’s going to go to court and the wall won’t get built,” Sen. Ron Johnson of Wisconsin told CNN’s Jake Tapper on “State of the Union.”

Instead, Johnson said, Trump and congressional Republicans should “keep pressure on Democrats to actually come to the negotiating table in good faith and fund what they’ve supported in the past.”

Congressional Democrats are engaged in a more than three-week battle with Senate Republicans and the White House over funding for a wall along the southern border. Trump has been mulling the use of a national emergency to fund the project, saying last week that he was nearing a decision on the matter and that he would take the step – which would likely be subject to an immediate legal challenge – if talks with Democrats continue to go nowhere.

Sen. Lindsey Graham, R-South Carolina, said Sunday that Trump told him earlier in the day that he’s still considering using his emergency powers to secure funding for the wall.

“I asked him, ‘Mr. President, if you want to go down the emergency path, I stand with you.’ He said just 30 minutes ago, ‘That’s my last — last option. I think the legislative route is the best way to go. Let’s make a deal, but I’ll do it if I had to,’” Graham told “Fox News Sunday” host Chris Wallace.

“I would urge (Trump) to open up the government for a short period of time, like three weeks, before he pulls the plug. See if we can get a deal,” Graham said. “If we can’t at the end of three weeks, all bets are off, see if he can do it by himself through the emergency powers. That’s my recommendation.”

Johnson suggested that Congress pass legislation to pay federal employees who are currently working without pay.

Johnson said he was planning to introduce a bill Monday and hopes Senate Majority Leader Mitch McConnell will bring it onto the floor, and that it will eventually have the support of both Democrats and the President.

An ‘unorthodox’ President

Johnson also responded to a report from The Washington Post that said that Trump has gone to “extraordinary lengths” to conceal details of meetings he’s had with Russian President Vladimir Putin. The report cited several officials who said they have never gotten a “reliable readout” of a two-hour meeting in between the to leaders in Helsinki, Finland, last year.

“But you said earlier this is not a traditional President. He has unorthodox means,” Johnson told Tapper. “But he is President of the United States. It’s pretty much up to him in terms of who he wants to read into his conversations with world leaders. That’s just the basic fact.”

Johnson suggested that leaks from within the administration may be a possible explanation for Trump’s behavior.

“Well, again, I don’t want to go speculate, beyond the fact that I know he was burned by leaks in other areas. And he was pretty frustrated by it. So, that might be – that might be one explanation,” he said.

CNN’s Eli Watkins contributed to this report.