'90 Day Fiancé' Stars Armando and Kenny Reunited in U.S. Amid Daughter's ICU Stay

"90 Day Fiancé" stars Armando Niedermeier-Rubio and Kenny Niedermeier have been reunited in the United States as their 13-year-old daughter receives urgent treatment for an unexplained brain bleed ... and the sweet reunion is on video.

You can watch the emotional video here -- Kenny and Armando embrace outside the Phoenix, Arizona, hospital treating Hannah in the ICU after they fought for the latter's entry into the U.S. on an emergency visa.

Next, Armando is overcome with emotion as he sees Hannah for the first time in person since she was transferred to the United States for testing earlier this week ... he whispers to her and kisses her on the forehead. Though she looks fragile, she's able to crack a smile.

Kenny and Armando also had a teary-eyed reunion with Armando's mom -- also seen in the gallery above. Kenny tells TMZ she had no idea Armando would be showing up late afternoon Friday. She and Kenny had both been by Hannah's side in the days prior as Hannah underwent rounds of tests to get to the bottom of her medical emergency.

Unfortunately, docs have still not figured out why the young teen had blood in her brain, which, as we told you ... left half her face "droopy" and half her body immobile on Tuesday, prompting her hospital visit.

Kenny tells us the lack of answers is "still very frustrating," but he's happy to see Hannah "improving and making headway."

He adds of their heartwarming reunion, "In the video she was in shock after seeing her father and she kept asking if it was real. She seems to even be improving more since his arrival."

TMZ broke the news that Armando was denied entry to America at the Mexican border as Hannah was receiving critical care. The couple's immigration attorney, Kelsey Zubkoff, told us she was working on all options to expedite their spousal visa or obtain an emergency order that allowed Armando to gain access to the U.S. to be with Hannah.

It turns out the effort worked with the help of several key players. Kenny tells TMZ ... he, Armando, and Kelsey paired up with Congresswoman Adelita Grijalva of Arizona, who advocated for Armando obtaining an emergency humanitarian visa, with the help of supporting letters from Arizona Senator Mark Kelly.

He says the exposure from concerned fans was also a huge help and says they're "very thankful for the amazing Customs & Border Patrol Officers in Arizona who ultimately approved and signed off on his visa."

Kenny tells TMZ he wants fans to know how thankful their family is for the thousands of messages of support, bringing attention to the case, and for the dedicated fan who launched a GoFundMe for Hannah.