Republican lawmakers have expressed "disbelief" that President Donald Trump invited Taliban leaders to Camp David so close to the anniversary of the 9/11 terror attacks.

"As we head into the anniversary of 9/11, I do not ever want to see these terrorists step foot on United States soil. Period," Rep. Michael Waltz of Florida told CNN on Sunday.

The US withdrawal from Afghanistan is now up in the air, and the longest war in US history has no clear end in sight.

The US faces escalating crises with Iran and North Korea that have been driven by Trump's policies and decisions. The Taliban invitation and subsequent criticism adds to an expanding list of foreign policy controversies and failures for the president ahead of an election year.

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A number of Republican lawmakers have excoriated President Donald Trump for inviting Taliban leaders to Camp David for a secret meeting, which adds to a rapidly expanding list of foreign policy controversies and failures for the president ahead of an election year.

Trump took to Twitter on Saturday to announce he'd canceled the meeting over a recent Taliban-claimed attack that killed a US soldier. He also said he's scrapping peace talks with the Taliban altogether.

"Unbeknownst to almost everyone, the major Taliban leaders and, separately, the President of Afghanistan, were going to secretly meet with me at Camp David on Sunday. They were coming to the United States tonight," Trump tweeted.

"Unfortunately, in order to build false leverage, [the Taliban] admitted to an attack in Kabul that killed one of our great great soldiers, and 11 other people," Trump added. "I immediately cancelled the meeting and called off peace negotiations."

Some Republican lawmakers are seemingly disgusted the US was negotiating with the Taliban on any level, and scoffed at the idea of its leaders coming to the US so close to the anniversary of the 9/11 terror attacks; the US declared war on the Taliban for harboring Osama bin Laden and other terrorists a month after the 2001 attacks.

Rep. Adam Kinzinger of Illinois, an Air Force veteran who served in Afghanistan as well as Iraq, told CNN on Sunday he's in "disbelief" that Taliban leaders were set to come to a region in the US so close to where the attacks occurred "in the week of 9/11."

"Negotiations between nation states can happen there, but a terrorist organization that doesn't recognize nation states, that kills innocent women and children, that denies women the right to really even be in the same room as their husbands ... to have them at Camp David is totally unacceptable," Kinzinger said.

In a tweet, Kinzinger also said, "Never should leaders of a terrorist organization that hasn't renounced 9/11 and continues in evil be allowed in our great country. NEVER. Full stop."

Rep. Michael Waltz of Florida, a member of the House Armed Services Committee, on Sunday told CNN: "As we head into the anniversary of 9/11, I do not ever want to see these terrorists step foot on United States soil. Period."

Rep. Liz Cheney of Wyoming in a tweet said, "Camp David is where America's leaders met to plan our response after al Qaeda, supported by the Taliban, killed 3000 Americans on 9/11. No member of the Taliban should set foot there. Ever. The Taliban still harbors al Qaeda."

Cheney also said, "The President is right to end the talks."

Fearing his wrath and the electoral consequences, Republican lawmakers rarely criticize the president these days, which makes the public rebuke of the Taliban invitation significant.

Despite the criticism, Secretary of State Mike Pompeo defended the move and on Sunday said, "It's almost always the case. ... that you don't get to negotiate with good guys." He also referred to Camp David as the "perfectly appropriate place" for such talks.

Trump appears desperate for a win on the global stage, but faces an utter quagmire in Afghanistan.

Trump campaigned on ending America's involvement in forever wars, and ending the conflict in Afghanistan — the longest war in US history — has been essential to that goal.

The US has few solid options for an exit from Afghanistan, which was recently ranked the most violent country in the world, and has seemingly accepted peace talks with the Taliban as one of the least-awful routes forward.

But with ongoing, deadly Taliban attacks and a surging ISIS-affiliate also wreaking havoc in Afghanistan, that task has proved difficult for Trump.

In his apparent desperation for win on the global stage, Trump turned to inviting Taliban leaders to the presidential retreat at Camp David, a site with a storied history when it comes to US diplomacy.

But Trump reportedly overruled his top advisers with this move, including Vice President Mike Pence. Behind-the-scenes, National Security Adviser John Bolton and defense officials warned Trump that inviting "a designated terrorist organization" to Camp David would "set a terrible precedent," Foreign Policy reported. On Monday, Trump and Pence disputed reports that Pence and other advisors had disagreed with Trump's plan to hold talks.

This all occurred less than a week after the top US negotiator in the US-Taliban talks said a peace deal had been met "in principle," which would involve withdrawing roughly 5,400 US troops from five bases in Afghanistan within 135 days.

As the war in Afghanistan closes in on its 18th anniversary, a path for the US to exit the country is even less clear. Trump on Monday declared that negotiations with the Taliban "are dead."

Trump has also contributed to the Iran crisis and the stalled talks with North Korea.

The Taliban-Camp David debacle occurred virtually at the same time as Iran took another major step away from the 2015 nuclear deal that Trump withdrew the US from in May 2018.

The president's decision to pull the US from the deal — move that ran contrary to the advice of nuclear experts and was condemned by key allies — has spiraled into a crisis that has led to fears of yet another conflict in the Middle East. The lead US negotiator in the deal last week told Insider that Iran appears "emboldened" as it takes steps toward being able to produce a nuclear weapon, as Europe desperately scrambles to save the agreement.

Read more: Trump's hardline campaign against Iran is failing to check its nuclear ambitions and risking a 'catastrophic' war

Meanwhile, despite two summits and an impromptu meeting with North Korean leader Kim Jong Un, Trump has also not secured the denuclearization of the Korean Peninsula. Along these lines, Pompeo is concerned the administration is being "strung along" by the rogue state, the New York Times recently reported.

US President Donald Trump and North Korea's leader Kim Jong-un talk before a meeting in the Demilitarized Zone (DMZ) on June 30, 2019, in Panmunjom, Korea. BRENDAN SMIALOWSKI/AFP/Getty Images

Trump has also dismissed the significance of recent short-range missile tests by North Korea, but experts and former US military officials have expressed concerns that the president is essentially giving Pyongyang a greenlight to develop more advanced missile technology that could pose a threat to US allies like Japan and South Korea — as well as thousands of US troops stationed in the region.

"Nuclear or not ... these are missiles that do threaten our two most important allies and our principal allies in northeast Asia," retired US Army Gen. Vincent Brooks, a former commander of US Forces Korea, recently told CNN. "This has to be something that the US is drawn into addressing."

In short, with Republican lawmakers and top advisers expressing doubts and pushing back, US allies getting more and more nervous, US adversaries increasingly acting out, and several escalating crises across the world — Trump's foreign policy is in shambles.