Malaysia had previously been warned by China through a diplomatic note, asking Malaysia to stop its activities in the oil-rich waters off Sarawak.
However, Prime Minister Anwar Ibrahim ignored the warning and insisted that Malaysia would maintain its right to continue oil and gas exploration in the region.
Anwar also affirmed Malaysia's stance of rejecting territorial claims from China.
Recent reports indicate that three Chinese coast guard vessels may have entered Malaysia's Exclusive Economic Zone (EEZ), near an oil rig operated by Petronas in the Kasawari gas field.
Malaysia's Exclusive Economic Zone (EEZ) is a maritime area that extends up to 200 nautical miles from the country's coastline.
Within this zone, Malaysia has special rights over the exploration and use of marine resources, both living and non-living, including the power to exploit resources such as oil, natural gas and fisheries, as well as manage and conserve the marine environment.
The EEZ includes the waters around Peninsular Malaysia and the states of Sabah and Sarawak on the island of Borneo.
This zone is an area rich in natural resources estimated to be worth billions of ringgit. The incident is tied to China's extensive claims in the South China Sea, based on the "nine-dash line," which overlaps parts of Malaysian waters off Sabah and Sarawak.
Wisma Putra declined to comment on the invasion, stating that it was under the responsibility of the defense ministry.
They however insisted that Malaysia is still committed to using diplomacy to protect its sovereignty.
