> Bordered by Russia and China, Mongolia describes the United States as its most important “third neighbor.” In 2019, the United States and Mongolia upgraded their bilateral relationship to a Strategic Partnership.
> Mongolia deployed troops to Iraq from 2003 through October 2008. In Afghanistan, Mongolian soldiers supported Coalition operations for 18 years, with withdrawal underway in 2021 in coordination with the planned exit of U.S. forces. Training and equipment provided by the U.S. government support the professionalization of Mongolia’s defense forces and their continued engagement in United Nations peacekeeping operations. The United States military also regularly participates in Mongolia-hosted peacekeeping and humanitarian relief exercises, including the annual Khaan Quest exercise.
> In the years since Kazakhstan’s independence, the two countries have developed a strong and wide-ranging bilateral relationship, jointly referred to as an enhanced strategic partnership since 2018.
> Kazakhstan’s military participates in U.S.-funded military exercises like Steppe Eagle, Viking, Eager Lion, and Shanti Prayas.
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> North Korea
The Russian border with North Korea is about 20 miles long.
> For 20 years, Iranian officials have said they wanted the U.S. military out of Afghanistan. Iran supplied Afghan insurgents with weapons to use against American soldiers. It sheltered Al Qaeda’s top leaders in Tehran. It courted the Taliban with diplomatic visits, covertly and then publicly.
The best I can find is an "enemy of my enemy" relationship, which has never been considered an alliance.
>For decades, Tehran has supported the Hazara, a Shia minority and the third largest ethnic group in Afghanistan. In the 1990s, the Taliban government repressed the Hazara—excluding them politically, isolating them economically, and killing more than 1,000—during the civil war that erupted after the 1989 Soviet withdrawal. Tensions heightened in 1998, when the Taliban killed nine Iranian diplomats working at a consulate in northern Mazar-i-Sharif. After the 9/11 attacks and the U.S. invasion of Afghanistan, Iran worked closely with the United States and regional powers to establish a new Afghan government free of the Taliban.
> Iran’s relationship with the Taliban shifted, however, as U.S. and NATO forces stayed in Afghanistan. Tehran viewed the Taliban as a useful tool to counter U.S. influence on its borders. It provided Taliban forces with enough military equipment to pressure the United States but not enough to generate American military retaliation. In 2016, the Taliban chief, Mullah Akhtar Mansour, was killed in a U.S. drone strike as he returned from a secret visit in Iran to his sanctuary in Pakistan. By 2017, Russia reportedly used Iran to funnel weapons to the Taliban.
> And Mongolia
https://www.state.gov/u-s-relations-with-mongolia/
> Bordered by Russia and China, Mongolia describes the United States as its most important “third neighbor.” In 2019, the United States and Mongolia upgraded their bilateral relationship to a Strategic Partnership.
> Mongolia deployed troops to Iraq from 2003 through October 2008. In Afghanistan, Mongolian soldiers supported Coalition operations for 18 years, with withdrawal underway in 2021 in coordination with the planned exit of U.S. forces. Training and equipment provided by the U.S. government support the professionalization of Mongolia’s defense forces and their continued engagement in United Nations peacekeeping operations. The United States military also regularly participates in Mongolia-hosted peacekeeping and humanitarian relief exercises, including the annual Khaan Quest exercise.
Seems like an "ally" to me.
> Kazakhstan
And while not as close, still maybe an "ally"?
https://www.state.gov/u-s-relations-with-Kazakhstan/
> In the years since Kazakhstan’s independence, the two countries have developed a strong and wide-ranging bilateral relationship, jointly referred to as an enhanced strategic partnership since 2018.
> Kazakhstan’s military participates in U.S.-funded military exercises like Steppe Eagle, Viking, Eager Lion, and Shanti Prayas.
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> North Korea
The Russian border with North Korea is about 20 miles long.