Senior Vice Foreign Minister Seiji Kihara said Japan is ready to lead the way in putting the Comprehensive Nuclear Test Ban Treaty into force at an early date.

Kihara signaled the government's stance in a speech to a one-day ministerial-level meeting in Vienna to commemorate 20 years since nations began signing the CTBT.

He also called on nuclear powers to declare a temporary halt to tests involving nuclear blasts, and encouraged visits to Hiroshima and Nagasaki, the world's only atom-bombed cities.

The CTBT aims to establish a verifiable global ban on all types of nuclear tests. The pact has been signed by 183 countries and ratified by 164.

To take effect, the CTBT must be signed and ratified by the 44 countries that had nuclear reactors for research or power generation while the treaty was under negotiation. Eight of those states — the United States, China, Egypt, India, Iran, Israel, North Korea and Pakistan — have yet to ratify it.