"To qualify as an antique, an item must be more than 100 years old and meet other requirements under the Endangered Species Act."
"The onus will now fall on the importer, exporter, or seller to demonstrate that an item meets these criteria."
Other measures include limiting to two the number of African elephant sport-hunted trophies that can be imported by an individual each year. The crackdown on ivory is a key aspect of a new national strategy for combating wildlife trafficking, also unveiled Tuesday, that has been in the works for some time.
During a trip to Tanzania last year, President Barack Obama signed an executive order for a $10 million program to reduce the practice in Africa. That led to the setting up of a task force to develop the strategy to crack down on the lucrative trade -- estimated to be worth between $7 and $10 billion a year.
"The United States will continue to lead global efforts to protect the world's iconic animals and preserve our planet's natural beauty for future generations," the White House said.