(Adds comments by lawmakers)
By Susan Cornwell
WASHINGTON, June 25 (Reuters) - U.S. House Democrats said they plan to pass a $4.5 billion aid package aimed at addressing the migrant surge along the U.S.-Mexico border later on Tuesday, citing an urgency to act following reports of poor conditions facing young children at overcrowded facilities.
"This week we have to solve the humanitarian crisis," Hakeem Jeffries, the House of Representatives Democratic Caucus chairman, told reporters, predicting that the funding package would pass the House with a "strong Democratic vote."
Lawmakers were rushing to add language before the vote to mandate better health and nutrition standards at border facilities. That came after some liberal Democrats expressed alarm that not enough was being done to improve conditions at the border, where the number of migrants apprehended surged in May to the highest level since 2006.
Last week, the Associated Press reported on squalid conditions facing migrant children being detained by U.S. authorities, including a lack of access to food, beds and hygiene products such as soap and toothpaste.
Republican U.S. President Donald Trump, despite having requested the $4.5 billion border aid package, on Monday night threatened to veto the House bill, saying the provisions added by Democrats - who control the chamber - would make the country "less safe."
But Jeffries said he expected Trump to sign the bill into law despite his threat, citing the president's recent reversals on other issues such as tariffs.
"There is no decency to having these children subjected to these horrific conditions," Jeffries said.
House Speaker Nancy Pelosi, seeking to galvanize her caucus, told them the House would need a strong vote to prevail.
"A vote against this bill is a vote for Donald Trump and his inhumane, outside-the-circle of civilized attitude toward the children," she said at a closed-door Tuesday morning meeting, according to a senior Democratic aide.
Democratic leaders said they would add language to protect the health of migrants in the custody of U.S. Border Patrol agents, including standards for medical care and nutrition. The bill's language would also set a three-month limit for any unaccompanied child migrant to spend at an intake shelter unless notice is given.
It was unclear whether the changes would be enough for some Democrats who fear the Trump administration could use some of the money for other purposes, such as deportations of migrants.
Representative Ilhan Omar said she objected to $155 million in the bill that would go to U.S. marshals, a law enforcement agency within the Department of Justice.
"There's no good outcome here," said Representative Alexandria Ocasio-Cortez, who has compared the detention centers for undocumented immigrants at the border to "concentration camps." She said she is worried over whether the funding will "go to the places that we need it to go."
The House legislation would also reinstate hundreds of millions of dollars in aid to El Salvador, Guatemala and Honduras that was cut off by the Trump administration.
The Republican-majority Senate was proceeding with its own, bipartisan, $4.6 billion version of the legislation and was expected to vote soon.
(Reporting by Susan Cornwell Writing by Susan Heavey Editing by Bill Berkrot, Jonathan Oatis and Leslie Adler)
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