The government is considering new legislation that would allow Japan to freeze the assets of people deemed terrorists to strengthen couterterrorism measures ahead of the 2020 Olympic and Paralympic Games in Tokyo, a government source said.

The legislation, which might be submitted to the Diet in the fall, is likely to draw fire for allowing people to be labeled terrorists at the government's discretion, and for threatening to infringe on property rights guaranteed by the Constitution.

The move comes as Prime Minister Shinzo Abe's administration considers criminalizing the act of plotting with others to commit serious crimes, such as murder, as part of its anti-terrorism efforts.

But given the strong public opposition, the government is trying to find a way of eradicating sources of revenue for those it considers terrorists.

At present, the government regulates money transfers to groups and individuals overseas that are designated as terrorists in accordance with U.N. Security Council resolutions.

As of February, 85 groups and 374 individuals were subject to limits under the Foreign Exchange Control Law.

But what to do with money transfers to and financial deals conducted with certain activists in Japan has been left up to financial institutions.

The government hopes to develop a list of people and organizations deemed terrorists, for use alongside a list of terrorists designated under UNSC resolutions, the source said Saturday.

Under the legislation, financial institutions will have to get permission to execute money transfers to people and groups on the list, as well as to open saving and trust-banking accounts with them — effectively freezing their assets.