President Ferdinand Marcos Jr. said on Monday the presence of a Russian attack submarine in the Philippines' exclusive economic zone (EEZ) in the South China Sea was "very worrisome". "That's very concerning.

Russia is surprised by the reaction of the Philippines to the passage of a submarine of the Russian Navy in the exclusive economic zone of this country. The vessel's stay was absolutely legitimate, Russian Foreign Ministry spokeswoman Maria Zakharova said at a briefing.

Russia’s embassy in Manila on Wednesday said its submarine which passed through the South China Sea and the Philippines’ exclusive economic zone did not violate international law. The vessel, it added,

Tensions between Russia and the Philippines escalated as the Philippine military deployed a navy ship and air force planes to shadow a Russian submarine in the South China Sea last week, security officials said.

The submarine is capable of firing Kalibr cruise missiles that have seen extensive use in strikes against Ukraine.

President Ferdinand Marcos Jr. said on Monday the reported presence of a Russian submarine in the Philippine's exclusive economic zone (EEZ) in the South China Sea was "very worrisome". Marcos did not elaborate on the submarine's reported presence,

Philippine President Ferdinand Marcos on Monday described as "very worrisome" the presence of a Russian attack submarine off the country's coast in the disputed South China Sea.

A Russian submarine was detected in the South China Sea, raising concerns in the Philippines as military tensions escalate in the region.