The Meteorological Agency would be allocated a 425 million yen (3.6 million dollars) budget in the next fiscal year for placing supersensitive seismometers about 800 meters (496 miles) underground in several complexes in central Japan, it said in a statement.

The measure "will reduce time necessary for analysis of seismic waves that are possibly not generated from natural earthquakes", it said.

The agency will also upgrade the data transfer capability between observation rooms in those complexes and the agency's headquarters.

In the wake of the declared nuclear weapons test by Pyongyang, the Meteorological Agency announced that it detected seismic waves which were different from natural waves.

It said it detected seismic waves measuring magnitude 4.9 on October 9, after North Korea said it had conducted its nuclear test.

But it took a few hours for the Meteorological Agency to determine if they were waves from a natural earthquake or unnatural ones from the test.

Japan boasts one of the world's most advanced quake-detecting systems, as the country lies at the junction of four tectonic plates and endures about 20 percent of the world's most powerful earthquakes, which frequently jolt Tokyo and other major cities.