Secretary-General António Guterres expressed his deep concern after reports of a tsunami and ash affecting Tonga following the eruption on an undersea volcano near the Pacific nation.

The UN chief also aired his concern about the tsunami warnings that have been issued in other countries such as Australia, New Zealand, Japan and the United States.

“The United Nations offices in the Pacific are closely monitoring the situation and are on standby to provide support if requested. The Secretary-General is grateful to countries that have already offered their support”, UN spokesperson Farhan Haq said in a statement published on Saturday.

According to the Tonga Geological Services, a massive underwater volcano erupted just before sundown on Friday with plumes reaching more than 12 miles above sea level. A cloud of ash and steam reached about 150 miles across, an event captured by satellite images that have been shared by various meteorological agencies.

There has not been an immediate report of injuries or on the extend of the damage due to the nation’s current lack of connectivity.