The Supreme Court is to consider whether a US branch of a Brazilian religion can import an hallucinogenic tea used as a sacrament.
An appeals court ruled the sacramental use of the tea cannot be banned because of a 1993 religious freedom law.
The hoasca tea which comes from the Amazon contains an illegal substance that can pose health hazards.
But adherents of the O Centro Espirita Beneficiente Uniao do Vegetal religion say the tea connects them to God.
Founded in Brazil in 1961, the religion is a mix of Christian and indigenous South American beliefs.
It has about 8,000 followers in Brazil and since 1993, around 130 in the US, centred around a branch in Santa Fe, New Mexico.
In 1999, US customs officials seized a shipment of three drums labelled "tea extract" sent from Brazil to the US branch.
Thirty gallons (136 litres) of the tea was also taken from the home of Jeffrey Bronfman, the head of the church's American chapter.
The tea contains dimethyltryptamine, or DMT, which the government says is unsafe for use, even under medical supervision.
But lawyers for the group cited experts who maintain sacramental use of the tea causes no harm.
They called for an injunction to prevent the authorities from impounding the tea and to allow its importation and use in church services.
The Justice Department called for a Supreme Court review after the government lost an appeal.
"The ... decision has mandated that the federal government open the nation's borders to the importation, circulation and usage of a mind-altering hallucinogen," acting Solicitor General Paul Clement of the Justice Department said.
The Supreme Court will hear the case and announce a decision during its next term which starts in October.