SAN FRANCISCO (AP) — A soldier welcomed his Afghan interpreter to the United States on Wednesday after buying him a plane ticket to ensure his quick arrival amid concerns the Trump administration might try to expand its travel ban to Afghanistan.

Army Capt. Matthew Ball yelled "Qismat!" as he ran and then hugged Qismat Amin at San Francisco International Airport in a series of emotional embraces that marked the end of a yearslong battle to get the translator out of his war-torn country.

"I'm so happy," Ball told The Associated Press after welcoming Amin. "Yeah it feels great. I'm happy to see him. I'm sort of overwhelmed. He's here. It's been a long time."

The interpreter waited nearly four years for his special immigrant visa. He lived in hiding after receiving death threats from the Taliban for helping American troops.

His visa arrived two days after President Donald Trump signed an executive order suspending the nation's refugee program and temporarily halting immigration from seven Muslim-majority countries.

Afghanistan was not among them, but U.S. officials said shortly after the order was signed that the list could be expanded to include other countries. The ban has since been placed on hold while it's being debated in the courts.

Ball bought Amin a $1,000 plane ticket to San Francisco to get him to the U.S. as soon as possible.

Amin has said he was nervous he would not feel welcome after Trump's order because he is an immigrant and Muslim. But those fears faded after he arrived to Americans holding signs that read "Welcome to America" and "Welcome Home."

"Right now, I don't know what to say. I forgot my words," he said. "Actually this has made me much, much stronger, seeing people with the welcome signs. I feel like I got a huge family right now, and I got a big family in Afghanistan. But right now I got a way bigger family than I ever expected."

Ball, a law student at Stanford University, led a letter campaign with fellow students, including many veterans, lobbying Congress to inquire about why it was taking so long for Amin to get a visa.

More than 13,000 Afghans and their immediate family members have been waiting to get a special immigrant visa for aiding the U.S. mission, according to the U.S. State Department.

Congress approved an additional 1,500 visas in December and extended the program until the end of 2020, but advocates say the number is woefully inadequate.

Ball said the U.S. government should speed up the yearslong visa process for interpreters and cultural advisers in Afghanistan because their lives are at risk after helping U.S. troops.

America's longest war, which began in response to 9/11, has grinded into its 16th year. Afghan soldiers and police have been suffering heavy casualties in their battle against a resilient Taliban insurgency, while U.S. forces continue to hunt down al-Qaida and Islamic State militants.

Ball said Amin protected his life during a yearlong mission in one of Afghanistan's most dangerous areas.

The former Army ranger, who is now in the Reserves, said he is happy he was able to return the favor by helping Amin get to safety.

Amin will live at Ball's home in Palo Alto for now.

Amin planned to call his mom to let her know he had arrived safely. Then he wanted to head to the beach to see the ocean for the first time.