The U.S. Embassy in Moldova expressed concern on Thursday about the arrest a Moldovan journalist in a separatist province on spying charges, and said his legal and human rights must be respected. Ernest Vardanean was arrested on suspicion of 'spying and high treason' on April 7 and ordered held in custody for two months in Trans-Dniester -- a tiny, poor and obscure area of Moldova that's a Russian-speaking Soviet-era relic. Word of his arrest came a week later. It was not clear what the charges centered on, although Vardanean has been critical of separatist authorities in his reports for the Russian news agency Novyi Region. If convicted as charged, Vardanean could be jailed for 20 years. U.S. Ambassador to Moldova Asif J. Chaudhry discussed the arrest with longtime separatist leader Igor Smirnov on April 14 in Tiraspol, the separatist region's capital. Smirnov told him the case was secret, the official Trans-Dniester Olvia-Pres news agency reported. 'The United States Embassy remains deeply concerned by the arrest ... and the procedures under which he is being held by the Trans-Dnistrian authorities. We strongly urge that international standards of fundamental human and legal rights be strictly observed in this case,' said a statement Thursday. It said the embassy was 'disturbed' by reports that neither Vardanean or his lawyer had been able to attend the pretrial detention hearing. Trans-Dniester broke away from Moldova in 1990, fearing it wanted to reunite with neighboring Romania. A war between Moldovan forces and separatists in 1992 killed 1,500 people. The region is not internationally recognized but is supported by Russia, which has around 500 troops stationed there to guard weapons storage facilities left by the Soviet military. Separatist authorities are scheduled to hold elections later this year. 