The magnitude 6.9 temblor hit at 6:39 a.m. (2139 GMT) and was centered off the coast of Sanriku in northern Japan, the agency said. The U.S. Geological Survey put the magnitude at 7.2.
There was no immediate explanation for the discrepancy. The quake hit at a depth of about 24 kilometers (15 miles), the U.S. agency said.
The Japanese agency said the tsunami could be 50 centimeters (19.5 inches) high and could reach Japan's Pacific Coast between 7:10 a.m.(2210GMT) and 7:30 a.m.(2230 GMT). Such waves are often barely noticeable in the ocean but can rise to greater heights once they arrive at shore.
There were no immediate reports of injuries, according to national broadcaster NHK, AP reports.
In recent years, genetics has become a cutting-edge science, not only in the professional field of biology, but also because of the enormous social reach of its discoveries and approaches. Not in vain, practically every day the press offers us the discovery of a new gene, a new hereditary determinant directly involved in the manifestation of diseases or physical characteristics.
On December 14, President Putin holds his annual Q&A session with Russian and foreign journalists. This conference is considered to be the beginning of his presidential campaign