An undersea volcanic eruption on Wednesday raised a tiny, new islet some 620 miles of Tokyo, Japan.

The Japanese coast guard has confirmed the birth of the new island. The new islet is about 200 meters (660 feet) in diameter and is located just off the coast of Nishinoshima, an uninhabited island in the Ogasawara chain, The Associated Press reported.

The Ogasawara Islands consists of 30 islets of various sizes scattered in the Pacific Ocean. These islands were formed by underwater volcanic eruptions. These islands have never been connected to any continent and so have many native creatures.

Japan's coastguard said that it has warned vessels to navigate carefully around the chain of islands as the volcano is billowing large amounts of ash and smoke.

"Smoke is still rising from the volcanic island, and we issued a navigation warning to say that this island has emerged with ash falling in the area," said a spokesman for the maritime agency, AFP reported.

Earthquake experts aren't sure if the islet will withstand erosion. If it does, then Japan can hope to expand its presence in the Pacific. The country has regular territory disputes with its neighbors- China and South Korea.

"If it becomes a full-fledged island, we would be happy to have more territory," governmental spokesman Yoshihide Suga said, according to Russia Today.

Recently, Pakistan too had witnessed birth of an island from the ocean offshore of the city of Gwadar, after a 7.7 earthquake hit the country. This mound was about 20 to 40 feet (6 to 12 meters) high and 100 feet (30 m) wide. Scientists believe that the mound in Pakistan could be a mud volcano.