WASHINGTON (Reuters) – U.S. President Donald Trump on Thursday threatened to use emergency powers to bypass Congress and get billions of dollars to pay for a wall on the U.S.-Mexico border, as a partial U.S. government shutdown over the issue stretched into its 20th day.

As he departed Washington for a trip to the Texas border with Mexico for wall-related events, Trump attacked the Democratic congressional leaders, who oppose his wall-funding demand, as less “honorable” than China, a rival power.

“I find China, frankly, in many ways to be far more honorable than crying Chuck and Nancy. I really do. I think that China is actually much easier to deal with than the opposition party,” Trump said, referring to House of Representatives Speaker Nancy Pelosi and Senate Democratic leader Chuck Schumer.

Trump is insisting that a government funding bill to end the shutdown must include $5.7 billion for a border barrier – his signature campaign promise. The standoff has left a quarter of the federal government closed down and hundreds of thousands of federal employees without pay.

A day after he stormed out of a meeting with Pelosi, Schumer and other Democratic leaders that was aimed at finding a deal to end the funding standoff, Trump headed to McAllen, Texas, on the Mexican border to highlight what he has argued is a crisis.

After the meeting Schumer accused the Republican president of “temper tantrum” tactics and Pelosi called Trump “petulant.”

Trump said his lawyers had told him he had the power to invoke national emergency powers to get his wall funded, a course of action that Democrats have said may be illegal.

“I have the absolute right to declare a national emergency,” Trump told reporters as he left the White House. “I’m not prepared to do that yet, but if I have to, I will.”

‘ALMOST SAY DEFINITELY’

If Congress fails to bend on the border wall funding, Trump said he probably would declare an emergency. “I would almost say definitely,” he said.

The declaration would circumvent Congress’s power over the national purse strings, giving Trump the ability to redirect money from the Department of Defense to his proposed wall.

Such a step likely would prompt an immediate legal challenge over constitutional powers from congressional Democrats. A subsequent court fight could be protracted, making room for the shutdown to be ended in the interim. The final outcome would then be left up to judges, not the president and Congress.

Even some Republicans who want to build a wall have said they do not want money to taken from the military for it and others see it as an overreach of executive powers.

There were no signals of a deal with Congress on Thursday. Pelosi told reporters Trump keeps “increasing the obstacles to finding a solution” to the shutdown.

“He loves the distraction that this is from his other problems,” she said at a briefing.

Pressure on both sides could intensify on Friday when about 800,000 federal employees – including border patrol agents and airport security screeners – miss their first paychecks.

About half of the workers who are deemed essential to national security – people such as border patrol agents, prison guards and airport employees – are working without pay. Others are staying home on furlough.

At the FBI, about 5,000 staff were furloughed, while the rest of the 13,000-member workforce continued on the job without pay, said Tom O’Connor, president of the FBI Agents Association.

Agents are concerned that operational funds the bureau needs to conduct investigations, including sensitive undercover operations, are beginning to dry up.

SHUTDOWN NEARING A RECORD

The lack of paychecks also could threaten the financial security of FBI personnel and conceivably raise questions about their security clearances, O’Connor said.

The shutdown, which began on Dec. 22, will be the longest in U.S. history if it is still under way on Saturday.

On Thursday, Trump planned to tour a border patrol station in McAllen, Texas, and get a briefing on border security at the Rio Grande River that separates the state from Mexico.

Trump says undocumented immigrants and illegal drugs are streaming across the border from Mexico, despite statistics that show illegal immigration there is at a 20-year low and that many drug shipments likely are smuggled through legal ports of entry.

Democrats accuse Trump of using fear tactics and spreading misinformation to fulfill a 2016 campaign promise as he looks toward his race for re-election in 2020.

Trump’s plan for a border wall – and to have Mexico pay for it – was a central promise of his 2016 presidential campaign.

He has since claimed that the renegotiated North American Free Trade Agreement with Mexico and Canada would pay for the wall, but the White House has not provided evidence of that.

“Obviously they are not going to write a check but they are paying for the wall indirectly many times over by the great trade deal,” Trump said on Thursday.

The new NAFTA deal has yet to be approved by Congress, where it will face pressure and scrutiny.