(CNN) -- The family and friends of Harry Devert, the American adventurer who disappeared in Mexico more than three weeks ago, has started a petition to try to get the attention of President Barack Obama as he heads to that country Wednesday.
"The petition was started in an effort to bring awareness to President Obama and his administration that many American citizens, including Harry, are missing in Mexico, and in turn ask the Mexican government's cooperation to conduct any and all investigations needed to locate our citizens," Darren Del Sordo, the lawyer and spokesman for Devert's family, told CNN.
The petition is on the White House's "We the People" website.
Obama will join Mexican President Enrique Pena Nieto and Canadian Prime Minister Stephen Harper for a one-day North American Leaders Summit in Toluca, Mexico, just 45 minutes from where Devert was last seen.
"If he can be aware of it, hopefully, there is something that can be done, something more than what has already been done," Devert's girlfriend, Sarah Ashley Schiear, told CNN.
Ann Devert, Harry's mother, also wrote a letter to the President.
"President Obama, I beseech you as a parent, please help bring Harry to safety," it reads in part. "I beseech you to ask President Pena Nieto to join you in our effort to help find Harry."
Devert, 32, left a job as a trader in finance to travel the world and has not been in touch with his mother or girlfriend in New York since January 25.
"He's dropped off the face of the Earth, it seems, and that's not who he is," Ann Devert told CNN. "And I can only think that he's hurt and needs us because there is no way he wouldn't have gotten word out to us."
Devert checked out of a bed and breakfast in the southwestern Mexican state of Michoacan and planned to travel to a beach in Zihuatanejo on the Pacific coast, which was in the final scene of the film "The Shawshank Redemption," according to family and friends.
"The clock is ticking, and every day we fear more that Harry is in a terrible position and needs us," Schiear said.
Schiear last heard from Devert in an ominous text via the WhatsApp messenger app.
"Just got an hour and a half long escort out of some area it was too dangerous for me to be," the message said. "Stopping for lunch and ... voila Internet. ... Gonna get back on the road soon. Apparently there's another military escort waiting for me in some other town... I'm running way late because of the crazy military stuff...hopefully get a chance to talk to you tonight when I (hopefully) finally arrive."
Because some areas in Mexico are reportedly unstable, those close to Devert fear he is in danger.
Ann Devert heard from a friend who recently returned from Michoacan, where vigilante self-defense groups in numerous communities have engaged in deadly confrontations with the Knights Templar drug cartel.
After vigilantes threatened to descend on a key cartel area last month, the Mexican government sent in thousands of troops and police to try to keep the peace. The government has even joined forces with the vigilantes as the Knights Templar become further entrenched in the agricultural state.
"This is an area in Michoacan that has been very dangerous," said Ann Devert, who has been in contact with The Missing Americans, a website dedicated to sharing information and resources about U.S. citizens missing in other countries.
Harry Devert had been escorted along Route 51, according to Jackie Burrell, a friend who is running the "Help Find Harry" page on Facebook.
"The biggest thing that we've been trying to figure out is who this escort was," Schiear said.
The Mexican government has been slow to respond, according to Burrell.
"We still don't have confirmation that there was in fact an escort by the military, and whether or not a second escort was arranged," Del Sordo added.
At this point, search efforts have provided no concrete answers.
"It could be anybody's kid that's on spring break. It could be anybody traveling abroad for any reason. It's a scary, scary thought," Schiear told CNN.
Help from the Obama administration and the Mexican government would aid the search for Devert, his loved ones say.
"We are doing everything in our power to find him. We need help. We need answers. We need Harry back," Schiear said.
CNN's Ray Sanchez and Alexandra Field contributed to this report.