(NewsNation) — The threat to Americans traveling or working in certain parts of the world continues to grow as enemies keep targeting them.

Since 2012, the James Foley Legacy Foundation says, the number of Americans considered wrongfully detained has sky-rocketed, leaving their families pleading for help.

One of them is the family of Wall Street Journal reporter Evan Gershkovich, who has been trapped in a Russian prison since he was arrested last year on espionage charges. These charges are highly questioned by both United States leaders and his employers.

“He’s the person who could make sense when things like this were happening in the world,” his sister, Danielle Gershkovich, said. “I miss him dearly.”

Danielle Gershkovich says the family exchanges one letter a week with her brother.

“Those are just a lifeline,” Danielle Gershkovich said.

President Joe Biden has called the threat of Americans being held on suspicious charges in certain parts of the world a “national emergency.”

The State Department has warned travelers from the United States about possible wrongful detention concerns in at least nine countries, including China.

Another American, Kai Li, has been behind bars in China since 2016, charged with stealing state secrets. His son, Harrison Li, says Kai is just an innocent American who’s been caught up in a “larger, sick game of hostage diplomacy.”

“The scary part is – as you see with the Americans being wrongfully detained around the world, including in China, these are all ordinary Americans, ordinary people, and unfortunately as a result, we don’t get the attention some others would,” Harrison Li said.

Freelance journalist Austin Tice, from Texas, is still in a Syrian prison, where he has been detained since 2012, while Marine veteran Paul Whelan continues to plead for help from a jail cell in Russia. Five years ago, Whelan was arrested and accused of being a secret agent.

His case continues to get attention. Recently, the U.S. State Department said Biden administration officials made a new and significant offer to secure Whelan’s and Gershkovich’s release, but Russia rejected it.

Signs of hope come every so often.

In Iran, the United States secured the release of five Americans during a September prisoner swap. Then, just weeks ago, ten American prisoners were released from Venezuelan custody in exchange for a close ally of the country’s president.

For the families with loved ones still facing so much uncertainty, though, Biden’s team says they will keep trying to bring them home.

“For me, and the president, these are not numbers on a piece of paper,” Secretary of State Antony Blinken has said. “They are real people whose lives have been torn apart.”