JERUSALEM — An American man has been charged in an Israeli court with illegal possession of weapons after he admitted under questioning that he had considered carrying out terrorist attacks, including against Islamic holy sites, Israeli officials said Tuesday.

The man, Adam E. Livix, 30, of Texas, was arrested on Nov. 19 after living illegally in Israel for 18 months, according to a police statement. It said that Mr. Livix had pretended to be a former member of the Navy SEALs, engaged in other acts of fraud and was found in possession of explosives stolen from the Israeli military. The police said he was a Christian.

He previously spent several months in the Palestinian territories. There, the Israeli police said, a Palestinian activist proposed getting him a sniper rifle to use to assassinate President Obama during his 2013 visit to the region, but Mr. Livix rejected that offer.

The police said that Mr. Livix was wanted in the United States on drug violations and that his case was being handled in cooperation with the F.B.I.