Trump also tweeted out a similar threat Sunday, which came as a surprise to many after a meeting last week between the president, Senate Majority Leader Mitch McConnell and Speaker Paul D. Ryan appeared to yield a tentative decision to punt a divisive fight over border wall funding until after the November elections.
His comments followed several days of shutdown threats in which he declared he saw "no problem" in shutting down the government to secure backing for one of his key campaign promises. He added that money for the wall was "not a question of if, it's a question of when".
Trump's Sunday tweet indicates he is still interested in a larger immigration bill that would limit family-based legal immigration, which opponents call "chain migration", as well as ending a diversity visa lottery and withholding funds from "sanctuary cities" which don't fully cooperate with immigrant deportation efforts.
Late Monday, Grassley and the Judiciary panel's top Democrat, Dianne Feinstein of California, sent a letter asking the inspectors general of the Homeland Security and Health and Human Services departments to investigate news organization's reports of abuse of immigrants at detention centres.
If a shutdown were to happen, it would be the third such instance in 2018, after a shutdown in January when the Trump Administration and Congressional Republicans wrestled with Democrats over protection for "Dreamers", a group of young immigrants.
US President Donald Trump returns to the White House holding his granddaughter Arabella's hand after spending a weekend in Bedminster, NJ on July 29, 2018 in Washington, DC. The Senate remains in session and is set to go on break the week of August 6 before returning for the rest of the month.
Both chambers will have a short window to act before government funding expires at midnight September 30. Trump has asked for $25 billion to build the wall.
Because Trump's wall was funded during the current fiscal year, it would continue for the length of the extension.
Some Republican lawmakers doubted the government would be forced to shut down.
Tension brews in Zimbabwe as opposition disputes election results
As Zimbabwe awaits the final result of the presidential election, both the MCD Alliance and ZANU-PF are confident of success. Mr Mnangagwa faces an unemployment crisis following the collapse of agriculture, hyperinflation and an exodus of investment.
"As far as the wall is concerned, we've gotten some wall funding already underway", Ryan said. The Senate Appropriations Committee, she said, was making progress and working "closely" with the administration. The House Appropriations Committee Homeland Security Bill contains $5 billion for "physical barriers and associated technology on the southern border".
"I don't think it would be helpful, so let's try to avoid it", Republican Senator Ron Johnson, chairman of the Senate Homeland Security Committee, said on CBS' "Face the Nation".
Two leading Democrats - Reps. They became vulnerable after Trump canceled the Deferred Action for Childhood Arrival program, or DACA.
A senior official at the USA agency charged with caring for migrant children believed separating them from their parents carried "significant risk" of harm and said on Tuesday concerns had been raised internally before the Trump administration made it official policy.
The hearing comes more than a month after President Donald Trump signed an executive order he said would put a stop to family separations, and days after a court-ordered deadline that spurred a massive effort to reunite more than 2,000 kids with their parents.
"The witnesses who testified (on Tuesday) couldn't answer some basic, serious questions about the implementation of the policy of separating parents and children with no plan to reunite them", said Sarah Turberville, director of the group's Constitution Project.
On another issue concerning the treatment of migrant children, a federal judge Monday found that government officials have been giving psychotropic medication to children at a Texas facility without first seeking the consent of their parents or guardians, in violation of state child welfare laws.
Following a day of relative silence on Twitter, Trump says: "Please understand, there are consequences when people cross our Border illegally, whether they have children or not - and many are just using children for their own sinister purposes".