President Trump pointed Tuesday to a new caravan heading toward the U.S. border from Honduras as he sought to gain leverage in his protracted fight with Democrats over border-wall funding that has pushed a partial government shutdown into its 25th day.

In a morning tweet, Trump referenced reports that about 600 Central American migrants are using the same route as have previous caravans and argued that “only a Wall” will work to protect the United States.

“A big new Caravan is heading up to our Southern Border from Honduras. Tell Nancy and Chuck that a drone flying around will not stop them,” Trump wrote, referring to House Speaker Nancy Pelosi (D-Calif.) and Senate Minority Leader Charles E. Schumer (D-N.Y.).

“Only a Wall will work,” Trump continued. “Only a Wall, or Steel Barrier, will keep our Country safe! Stop playing political games and end the Shutdown!”

Trump’s demand for $5.7 billion in border wall funding and steadfast resistance from Democrats have left Congress paralyzed, with no apparent end in sight to a shutdown impacting about a quarter of the federal government.

Trump’s citing of the caravan was reminiscent of a strategy employed in advance of last year’s midterm elections, when he repeatedly tweeted about migrants heading to the U.S. border in an attempt to motivate his political base to vote.

In another tweet Tuesday morning, Trump asserted that “Democrats will soon be known as the Party of Crime,” adding: “Ridiculous that they don’t want Border Security.”

Democrats have said they are willing to negotiate over border security once the government is reopened, but they reject a wall as an expensive and antiquated solution.

Trump also tweeted Monday that polls “are now showing that people are beginning to understand the Humanitarian Crisis and Crime at the Border.” He added, “Numbers are going up fast, over 50%.”

A Quinnipiac poll released Monday found that 54 percent of U.S. voters say there is a security crisis at the border, and 68 percent say there is a humanitarian crisis.

The same poll, however, found 55 percent of voters oppose a wall on the U.S.-Mexico border, while 43 percent are in favor.

The poll also found that 66 percent of voters say Trump and Republicans are responsible for the shutdown, while 36 percent say Democrats are responsible.

In another tweet, Trump questioned why Pelosi is being paid during the shutdown.

That prompted this response from her on Twitter: “@realDonaldTrump, stop holding the paychecks of 800,000 Americans hostage. There is no reason for them to be suffering right now. Re-open the government! #TrumpShutdown”

Trump also retweeted a tweet from his eldest son, Donald Trump Jr., which included a link to an op-ed from the Daily Caller that the publication said was written by an anonymous senior Trump administration official.

The author acknowledges that federal employees are starting to feel the strain of the shutdown but writes “for the sake of our nation, I hope it lasts a very long time.”

“The lapse in appropriations is more than a battle over a wall,” the author says. “It is an opportunity to strip wasteful government agencies for good.”

In his tweet, Trump Jr. writes that the piece is “worth the read.”

Trump has invited several moderate Democrats to lunch Tuesday in a bid to pick off some of the House majority party’s members.

Democratic leaders continued Monday to highlight the negative impacts of the partial shutdown.

The office of House Majority Leader Steny H. Hoyer distributed news accounts from all 50 states about how the shutdown is “hurting millions of Americans.”

Democratic House leaders also plan to continue to pass bills this week that would reopen shuttered federal agencies. Such bills passed last week were declared dead on arrival in the Republican-led Senate because Trump has threatened to veto them.

At a news conference Tuesday, House Minority Leader Kevin McCarthy (R-Calif.) said the Democratic tactics were not geared toward solving the problem.

“The only thing I see on the floor this week is political theater,” McCarthy said.

He called on Democrats to compromise.

“We need to secure our border,” McCarthy said. “That’s what this fight has been about from the very beginning.”