Japan's ambassador to the UN organisations in Vienna, Yukiya Amano, signed the agreement with the body that oversees the Comprehensive Nuclear Test Ban Treaty (CTBT) giving his country access to fast and reliable seismic and hydroacoustic data that will enable Japan to respond more quickly to possible tsunamis.

"We will have access to more accurate and more rapid information to enable us to issue a tsunami alert," Amano said at the signing of the agreement at the headquarters of the CTBT preparatory commission or CTBTO.

It was the first such agreement to be signed by the CTBTO and one of its member countries and is set to be followed by similar deals with other Pacific Rim countries, such as Australia, Indonesia, Malaysia and the Philippines, said CTBTO executive secretary Tibor Toth.

On the basis of the deal, the CTBTO would be in a position to provide "the speediest, most reliable and highest quality data," Toth said. "Within 30 seconds, around 90 percent of the information reaches the tsunami warning centre in Tokyo. The average speed for other systems is around 180 seconds."

The CTBTO has a worldwide network of well over 300 monitoring stations -- above ground, below ground and beneath the sea -- for the verification of possible nuclear tests.

But the CTBT, to which some 114 nations are party, cannot come into effect before it is embraced unanimously by a select group of 44 nations that includes China and the United States, which have so far failed to ratify it.

In the wake of the December 26, 2004 tsunami that killed nearly 220,000 people in southeast Asia, CTBTO decided to provide verification data and technologies that could be helped to detect tsunamis.