Japan tightened its border controls Monday to limit the spread of the new coronavirus that causes COVID-19, but government officials and legal experts point out the containment strategy may not be successful due to legal limitations.

Prime Minister Shinzo Abe announced Thursday that from Monday the nation would ask all those arriving from South Korea and China to self-quarantine for two weeks at designated facilities.

The measure took effect on 12:00 a.m. Monday and is set to continue through March 31.