WASHINGTON, DC (CNA/EWTN News) - The United States mustn't cut foreign aid while conflicts, famines, and a worldwide refugee crisis rage, Catholic leaders are insisting.

Amid a "huge, unprecedented refugee situation" around the globe and four countries with famines or on the cusp of famine "we're just extremely concerned that the resources won't be there to respond to those really critical humanitarian needs," Bill O'Keefe, vice president for government relations and advocacy at Catholic Relief Services, told CNA on Friday of President Donald Trump's proposed budget that cuts some foreign assistance.

President Trump's "skinny" proposed "America First" budget for FY 2018 - a more detailed plan will be released later -- increases defense spending and immigration enforcement, and makes significant cuts to the Environmental Protection Agency and the State Department, among other agencies and programs, to offset those increases.

"This includes deep cuts to foreign aid. It is time to prioritize the security and well-being of Americans, and to ask the rest of the world to step up and pay its fair share," President Trump stated in the proposal.

The proposal trims almost a third - 29 percent - of the International Affairs Budget, David Beckmann, president of the group Bread for the World, told CNA.

And while the number of persons displaced from their homes is at its highest ever recorded at over 65 million, with over 21 million of those refugees, the U.S. should not be cutting its foreign aid to vulnerable populations, CRS insisted.

With huge movements of people comes instability, O'Keefe said. "If we don't meet" the humanitarian needs of vulnerable populations, "people will move and that will be destabilizing."

106 faith leaders signed a letter sent to congressional leaders on Thursday in "support for the International Affairs Budget that every day brings hope to poor, hungry, vulnerable and displaced men, women and children around the world."

Signers of the letter included Cardinal Timothy Dolan of New York, Bishop Gregory J. Mansour of the Eparchy of Saint Maron of Brooklyn and chairman of the board of Catholic Relief Services, Archbishop Salvatore Cordileone of San Francisco, Archbishop Joseph Kurtz of Louisville, and Archbishop Jerome Listecki of Milwaukee.

"With just 1 percent of our nation's budget, the International Affairs Budget has helped alleviate the suffering of millions; drastically cutting the number of people living in extreme poverty in half, stopping the spread of infectious diseases like HIV/AIDs and Ebola, and nearly eliminating polio," they stated.

"Additionally, it promotes freedom and human rights, protecting religious freedom for millions around the world."

In Trump's budget proposal, foreign assistance would be targeted toward countries of greater "strategic importance" to the U.S.

This shifting of priorities could have serious consequences for the future of U.S. foreign policy, O'Keefe noted, as countries deemed "less strategic" for aid could see their societal problems greatly increase without assistance in the next few years.

"If you ignore countries that are fragile, poorly governed, with lots of poor and disenfranchised people, then they end up becoming strategic countries that you then have to fight wars in," he said.

"We'd like to see our government investing more in prevention, and in building the capacity of societies to deal with their own problems and in the diplomacy to resolve conflicts without military action."

He noted that the budget proposal keeps "much of the global health funding" like the PEPFAR program to fight AIDS in Africa, O'Keefe said, which is good.

However, the proposal targeted many other programs like the McGovern-Dole Food for Education Program, which "allows CRS to support basic education in rural school settings," O'Keefe said. The president had said that program "lacks evidence that it is being effectively implemented to reduce food insecurity."

The proposal also touches anti-trafficking programs and anti-gang programs, and the State Department's 60 year-old Food for Peace program would see cuts, CRS noted.

"We understand the budget challenges," O'Keefe insisted, while adding that "you're not going to be able to balance the budget on the one percent that goes to foreign aid," especially since it's already been trimmed disproportionately for the last nine years.

He added that domestic and international anti-poverty programs have "been squeezed" to make room for military spending, which would prioritize short-term goals over long-term stability.

Some domestic programs saw cuts, including "housing and heating for poor people," Beckmann noted, and certain block grants that provide funding for the program Meals on Wheels, a volunteer food delivery program to the elderly.

"How can you cut Meals on Wheels?" Beckmann asked.

The president of the organization, Ellie Hollander, explained what may be at stake in the proposal.

"The problem with a skinny budget is it is lean on details. So, while we don't know the exact impact yet, cuts of any kind to these highly successful and leveraged programs would be a devastating blow to our ability to provide much-needed care for millions of vulnerable seniors in America, which in turn saves billions of dollars in reduced healthcare expenses," Hollander stated.

Some of the other federal programs the President suggested cutting included the National Endowments for the Arts and the Humanities and some funding for Meals on Wheels and the National Institutes of Health.

Programs fighting opioid addictions would receive a half-a-billion dollar boost in Trump's plan, however. The Centers for Disease Control has labeled opioid overdoses an epidemic, and said that 33,000 people died from using prescription opioids and heroin in 2015.