WASHINGTON — President Donald Trump explicitly advocated depriving undocumented immigrants of their due-process rights, arguing that people who cross the border into the United States illegally must immediately be deported without trial. His tweets Sunday are sowing more confusion among Republicans ahead of a planned immigration vote this week.

In a pair of tweets sent while being driven to his Virginia golf course, Trump described immigrants as invaders and wrote that U.S. immigration laws are “a mockery” and must be changed to take away trial rights from undocumented migrants.

“We cannot allow all of these people to invade our Country,” Trump wrote. “When somebody comes in, we must immediately, with no Judges or Court Cases, bring them back from where they came. Our system is a mockery to good immigration policy and Law and Order. Most children come without parents.”

The president continued in a second tweet, “Our Immigration policy, laughed at all over the world, is very unfair to all of those people who have gone through the system legally and are waiting on line for years! Immigration must be based on merit — we need people who will help to Make America Great Again!”

The latest presidential exhortations came as House Republicans were preparing for a vote on immigration legislation, after a more hard-line bill failed last week. Neither bill has Democratic support, and prospects for the second one passing appeared dim, although the White House still supports it.

“I did talk to the White House yesterday. They say the president is still 100 percent behind us,” Rep. Michael McCaul, R-Texas, a co-sponsor of the bill, said on “Fox News Sunday.”

Some Republican lawmakers are preparing a more narrow immigration bill that would address one of the flaws in Trump’s executive order mandating that children and parents not be separated during their detention.

“I think, at minimum, we have to deal with family separation,” McCaul said.

The 1997 “Flores settlement” requires that migrant children be released from detention after 20 days, but the new GOP measure would allow for children and their parents to stay together in detention facilities past 20 days.

In the event that the broader immigration bill fails to pass the House this week, the White House is preparing to throw its support behind the narrower Flores fix, which is expected to garner wider support among lawmakers, according to a White House official.

This behind-the-scenes legislative work amounts to a reversal from Trump’s position on Friday, when he tweeted that “Republicans should stop wasting their time on Immigration until after we elect more Senators and Congressmen/women in November.”

The tweet demoralized Republicans as they headed home for the weekend but did not end talks about what the House might pass.

Marc Short, the White House director of legislative affairs, said Sunday that it was premature to announce which measures Trump would sign but urged Congress to act quickly to address the immigration issue broadly.

Brendan Buck, counselor to House Speaker Paul Ryan, R-Wis., said Sunday that a solution specifically dealing with family separation had been “a topic of discussion all week” but that there was not one policy or bill that Republicans had coalesced behind.

In a Sunday afternoon tweet, Senate Democratic leader Chuck Schumer of New York argued for “a czar to break through the bureaucracy and get these kids out of limbo and back in their parents’ arms.” On Sunday shows, Republicans echoed Trump, saying that Democrats were rejecting any serious solution in favor of inflicting political hurt.