WASHINGTON (AP) — The White House is following up its longshot roster of budget cuts with a wish list of $18 billion worth of immediate reductions, including cuts to medical research, infrastructure, and community development grants.

Like President Donald Trump's 2018 budget, which was panned by both Democrats and Republicans earlier this month, the proposals have little chance to be enacted.

But they could create bad political optics for the struggling Trump White House, since the administration asked earlier for $3 billion to pay for the Trump's controversial U.S.-Mexico border wall and other immigration enforcement plans. During the campaign, Trump promised Mexico would pay for the wall.

Now, the White House wants the wall and Pentagon increases be paid for using steep, immediate cuts to research into medical cures and funding for new roads and bridges here at home.

Unlike the budget document itself, the roster of cuts do not represent official administration proposals. Instead, they were sent to Capitol Hill as a set of "options" for GOP staff aides and lawmakers crafting a catchall spending bill for the ongoing budget year, which ends Sept. 30. That suggests the White House isn't determined to press the cuts.

The documents arrived as negotiations over a catchall spending package continue Tuesday with the aim of averting a partial government shutdown at the end of next month. The package would wrap up $1.1 trillion in unfinished spending bills and address the administration's request for an immediate $30 billion in additional Pentagon spending.

Those talks are intensifying, but Senate Republicans are considering backing away from a showdown with Democrats over whether to fund Trump's request for immediate funding to build a wall along the U.S.-Mexico border. Senate Democrats have threatened to filibuster any language providing money for the wall.

Asked about including Southern border wall financing in the broader spending package, Sen. Roy Blunt, R-Mo., a key negotiator, said, "They will not pass together. That's just my view."

Blunt added, "My view is there's a path to get 60 votes" in the Senate, the total required to overcome a Democratic filibuster.

"There is no path to put a supplemental (wall) as currently described on that package," said Blunt, a member of the Senate GOP leadership team and is major player on health and human services accounts.

The government would shut down except for some functions on April 29 without successful action on spending. GOP leaders are eager to avoid a politically damaging shutdown, especially in the wake of last week's embarrassing failure to pass the Trump-pushed bill to "repeal and replace" former President Barack Obama's landmark health care law and Trump's decision to abandon the effort.

Negotiators have made progress on the core elements of a dozen must-do funding bills but have ignored the White House's list of cuts in doing so.

But the White House badly wants funding for the Mexico wall and hasn't fully engaged in the Hill negotiations. Pitfalls and land mines lay ahead in the talks, and the situation is especially fragile because of divisions among GOP ranks and uncertainty over who's playing the lead role at the White House on the particulars of budget work.

The new list of cuts include $1.2 billion in National Institutes of Health research grants. The community development block grant program would be halved, amounting to a cut of $3 billion, and $500 million would be stripped from popular transportation project funding known as TIGER grants.

White House budget office spokesman John Czwartacki said the proposals were not being shared with the media. A Capitol Hill aide described the cuts to The Associated Press, speaking only on grounds of anonymity because the budget document is not yet public.