Vietnam has expressed strong criticism against recent activities by a Chinese research vessel and the Philippine coast guard in the contested South China Sea, charging both countries with infringing upon its sovereign rights.

The South China Sea, a pivotal maritime trade route accommodating over $3 trillion in annual ship-borne commerce, has been the focus of heightened tensions as Chinese and Vietnamese ships have engaged in multiple confrontations. These incidents have been prompted by the movement of a Chinese research ship within Vietnam's Exclusive Economic Zone (EEZ). Experts have surmised that the vessel was conducting a survey, which, without prior notification, is often perceived as a hostile act.

Vietnamese Foreign Ministry spokesperson Pham Thu Hang voiced her country's objections at a press conference, stating that such vessels were "violating the sovereign rights and jurisdictions of Vietnam". She added that Vietnam was implementing "appropriate measures" to safeguard its rights.

China, which lays claim to the majority of the South China Sea based on what it considers to be historical maps, has defended its actions, maintaining that scientific research is a routine activity in areas under its jurisdiction. This expansive claim encompasses waters within the EEZs of Vietnam and four other Southeast Asian nations.

Vietnam also denounced the Philippines for its installation of navigational buoys in five areas within its EEZ as a means of asserting sovereignty over the contested Spratly islands, to which Vietnam also asserts a claim.

Responding to the Philippines' actions, Hang stated: "Vietnam strongly opposes all acts violating Vietnam's sovereign rights."

Teresita Daza, a spokesperson for the Philippine Foreign Ministry, defended Manila's actions, stating that the deployment of buoys was in accordance with the country's rights as a coastal state under the U.N. Convention on the Law of the Sea. Speaking to Reuters over the phone, Daza asserted, "They are meant to improve safety of navigation in our waters and should be of no cause for concern."