State lawmakers committed past year to carry on spending, despite Trump's election, the decrease in unauthorised border crossings and the reality that many migrants surrender to U.S. officials as soon as possible in order to seek asylum.
The letter from Reed, of Rhode Island, and Durbin, of IL, comes on the heels of reports that Trump suggested the idea to "several advisors" after being disappointed by the amount of money allocated for border security in the $1.3 trillion omnibus.
U.S. Army General Joseph Votel, who oversees U.S. forces in the Middle East as the head of Central Command, said allied troops have made inroads in taking back Islamic State held territories, but said the group's presence "is not gone".
Trump has been seething since realizing the major spending bill he signed last month barely funds the "big, beautiful" border wall he has promised supporters.
Sparks didn't specify how much spending could be rescinded or in what categories, but Trump would likely seek to focus on domestic spending he has derided in recent tweets.
Many migrant advocate groups argue that given the scale of the armed law enforcement presence, the extensive surveillance infrastructure, fencing, and numerous checkpoints, the border is, in effect, already militarised.
Trump's comments came about two weeks after he signed a $1.3 trillion spending bill that funded the federal government through September 30.More news: Trump loads another tweet into the chamber - and fires on Amazon again
He's been complaining that USA borders are too porous and its immigration laws are too weak. But much of that money can only be used to fix existing segments, not build new sections. Under current law, unaccompanied children from countries that don't border the US are turned over to the Department of Health and Human Services and undergo often lengthy deportation proceedings before an immigration judge instead of being immediately deported.
The administration is also pushing Congress to terminate a 1997 court settlement that requires the government to release children from custody to parents, adult relatives or other caretakers as their cases make their way through immigration court. Such proposals are likely to face opposition from moderate Republicans and Democrats going into the midterm elections. It is not clear how widely the idea has been embraced by other top Republicans, including Speaker Paul Ryan or Senate Majority Leader Mitch McConnell. Under current law, unaccompanied children from countries that don't border the US are turned over to the Department of Health and Human Services and undergo often lengthy deportation proceedings before an immigration judge instead of being immediately deported.
The president fired off several tweets on Tuesday about the caravan march toward the "Weak Laws" border of Mexico.
Trump briefly considered vetoing the legislation both over its lack of funding for the wall and also the failure to include a fix for the expiring Deferred Action for Childhood Arrivals (DACA) program that granted protection for illegal immigrants brought to the country as children.
Notably, Trump's favored solution for extending the protections mustered only 39 votes in the Senate, meaning it couldn't have passed even if the rules had been changed. Two caravans traveled north previous year and others have made similar trips since 2010.
He tweeted earlier for the third day about the "caravan" of migrants heading north from Central America.