UPDATE 2-Arizona border activist told migrants he 'could not hide them'

(Adds prosecutor comment, trial schedule)

By Paul Ingram

TUCSON, Ariz., Nov 19 (Reuters) - An Arizona human rights activist charged with harboring two migrants who crossed the U.S.-Mexico border illegally testified that he told the men he "could not hide them" but let them stay in a building while they recovered from a desert trek.

Scott Warren, 37, appeared on Tuesday in his second federal felony trial this year after a Tucson jury was unable to reach a verdict in June on whether he broke the law by giving food, water and shelter to two Central American migrants.

The trial is likely to set a precedent on what kind of help Americans can legally give undocumented migrants as U.S. President Donald Trump makes tougher immigration enforcement a major re-election theme.

Warren was arrested on Jan. 17, 2018, at a building in Ajo, Arizona, around 103 miles (166 km) west of Tucson, where U.S. prosecutors accuse him of concealing Kristian Perez-Villanueva, then 23, and Jose Arnaldo Sacaria-Goday, 20.

The men from El Salvador and Honduras, respectively, testified last week they crossed the border and walked nearly 30 miles through the desert before sheltering in a building used by Warren's human rights group, No More Deaths (NMD).

Warren said he was "surprised" to find what looked like two "teenage boys" when he went to the ramshackle building known as "The Barn" on Jan. 14, 2018.

He gave the men medical checks, finding they both had blisters and scratches, with Sacaria-Goday showing cold-like symptoms and complaining of a bruised upper torso.

He said the men needed to recover rather than continue their journey through desert where "people are dying from exposure."

He described NMD's humanitarian aid, which includes leaving water in the desert for migrants, as akin to the work of international organizations in conflict zones.

Asked by U.S. prosecutor Anna Wright whether he knew both men were in the country illegally, Warren responded that he "could put two and two together."

Warren's intent remains a central issue in the case, as prosecutors have argued he deliberately sheltered the men from the U.S. Border Patrol, then gave them guidance on how to continue their journey.

Border Patrol agents had The Barn under surveillance and moved in to arrest Warren and the men after they allege he walked outside and gestured to the north to show them where to go.

Warren defended giving the men what he called "orientation," saying that under NMD legal protocols he was not allowed to provide them with directions.

Both sides will give closing arguments on Wednesday. (Reporting by Paul Ingram in Tucson Writing by Andrew Hay in Taos, New Mexico Editing by Matthew Lewis and Rosalba O'Brien)