WASHINGTON -- Barring last minute opposition from Congress, Saudi Arabia is poised to receive a hefty $1.3 billion weapons package that includes 13,000 “smart bombs” from the United States by the end of the year. But don’t necessarily expect it to be used to fight ISIS.

Critics say the payload of sophisticated weapons will instead bolster the Saudis' continuing air war against the Houthi rebels in Yemen. That campaign is drawing fire from human rights groups, who say the kingdom has been targeting civilians with American-made weapons, and may be responsible for war crimes.

“President Obama is poised to sell thousands of bombs and warheads to a government that unlawfully targets civilians,” Amnesty International, which has been lobbying hard for Congress to kill the deal, said in a statement Thursday.

More than 5,700 people, including at least 2,577 civilians — 637 of them children — have been killed in the eight months Saudi Arabia has led a coalition of Gulf States in the bombing campaign, according to the United Nations. Another 2.3 million have been displaced. Meanwhile, the Office of the UN High Commissioner for Human Rights found that "almost two-thirds of reported civilian deaths had allegedly been caused by coalition airstrikes.”

“By selling the Saudis the weapons included in the latest deal, the U.S. will be further implicated in possible war crimes committed in Yemen and it will be helping to fuel an unnecessary war,” charged Daniel Larison, senior editor at The American Conservative magazine.

“At the same time the Saudis are using U.S. weapons in Yemen, they and the other members of their coalition have withdrawn their small contributions to the campaign against ISIS and diverted their resources to the fight that they consider to be more important,” he added.

The coalition has denied the accusations in published reports. Saudi Arabia is determined to beat back the Houthis, who deposed President Abdrabbuh Mansour Hadi, in February. The Houthis are said to be getting support from the Iranians, and the conflict is largely seen as part of a regional stuggle between the Sunni Gulf States and Shia Iran.

After strikes killed 70 people at a wedding in Yemen in September, Saudi officials warned not to jump to conclusions. They have since blocked an international inquiry into war crimes there.  “We need to be careful about facts and fiction,” Saudi foreign minister Adel al-Jubeir told reporters at the time.

The concerns, however, have not escaped members of Congress, which has had 30 days to review the deal before it goes through.

While Sen. Bob Corker, R-TN., chairman of the Senate Foreign Relations Committee, supports the action in Yemen, he has requested “that the committee be notified of future weapons shipments to Saudi Arabia resulting from this proposed sale,” according to an email forwarded to Foxnews.com from the committee.

He is joined by ranking member Sen. Ben Cardin, D-Md., who has raised alarms about the human rights issue, along with other Democratic members.

They are not expected to stop the sale, however. It is the most recent in a long line of arms deals brokered with Riyadh -- $90 billion worth since 2010, according to the Congressional Research Service.

Reached for comment, the State Department, which engineered the sale, called Saudi Arabia “a key U.S. strategic partner within the region,” and that “the purchase of these munitions will rebuild Saudi Arabia’s inventory, helping them to meet their defense requirements over the long term.”

On the human rights issue, the State Department says it has “noted our concern several times regarding civilian casualties and deaths in Yemen,” and has encouraged the coalition to investigate “credible accounts of civilian casualties.”

“Ultimately, we want to see a diplomatic solution,” the agency said, and noted the start of peace talks in December, in concert with a seven-day ceasefire.

Saudi Arabia, a long time ally of the U.S. in the Middle East, has nonetheless been the subject of criticism on a number of fronts. In addition to its human rights record in Yemen, the kingdom has been cited for abuses at home, including beheadings over the last year for crimes such as “sorcery” and “apostasy” against Islam. The legal system is based on sharia law, and religious freedoms there are all but non-existent, say critics.

Saudi Arabia is also the birthplace of Wahhabism, the radical fundementalist strain of Islam practiced by global terror groups like ISIS today. While the kingdom has partnered in counterterrorism operations with the U.S. and its Gulf neighbors, it is also accused of turning a blind eye while the country’s elites pour billions into extremist mosques, madrassas, and terror-related organizations across the globe.

Tafheen Malik, one of the shooters in the recent San Bernardino attack, came to the U.S. from Saudi Arabia.

“At a minimum they have to stop aiding and abetting Wahhabism; I would hope that the administration would make that a condition,” said former Rep. Frank Wolf, R-Va., who is now the Jerry and Susie Wilson Chair in Religious Freedom at Baylor University, and presses often on Capitol Hill for protection of religious minorities in the Middle East conflict zones.

Saudi officials have long denied the complaints and have often pushed back against detractors. Early this year, they blocked an arms agreement with Sweden after its foreign minister Margot Wallstrom called the kingdom a dictatorship and criticized the sentence of 1,000 lashings it imposed on a blogger there. The kingdom called her remarks "offensive."

But the issue has become so pronounced in recent months due to the terror attacks in Europe, that world leaders are speaking out more. In a moment of candor this week, the German Vice Chancellor accused the kingdom of financing terror.

“We have to make clear to the Saudis that the time of looking away is over,” Vice Chancellor Gabriel Signar told Bild am Sonntag newspaper in an interview.

“Wahhabi mosques all over the world are financed by Saudi Arabia,” he added. “Many Islamists who are a threat to public safety come from these communities in Germany.”

Critics like Wolf say the U.S. has been trying to get Saudi Arabia and the Gulf states to step up their game in the fight against ISIS and maybe such a lucrative weapons package sends the wrong message.

“You need American intelligence, American special ops, but you need boots on the ground from Saudi Arabia, Qatar, Jordan,” he said. “They need to start participating. This is absolutely critical before giving them weapons and aid.”

Corker is not as willing to blame Saudi Arabia so quickly.

“(Corker) also believes the U.S. should encourage greater involvement of our coalition partners in the fight against ISIS, but he thinks the perception of U.S. disengagement resulting from the Obama administration’s approach to the region, especially after the Iran nuclear deal, is hindering that effort,” his office said Friday.

A breakdown of the munitions being sold to the kingdom can be found on the State Department website.