Taiwan has accused Beijing of escalating tensions after mainland Chinese coastguard and survey vessels carried out law-enforcement operations in waters off the island’s east coast.

Chinese state media said the operation was a “necessary action” to respond to Tokyo and Manila’s announcement late last month that they would begin talks on delineating their maritime boundaries in the region. That announcement was condemned by Beijing.

Taiwan’s defence minister Wellington Koo Li-hsiung on Monday described the move as a provocation and a form of “cognitive warfare” aimed at asserting mainland Chinese jurisdiction over waters that Beijing does not control.

“China intends to claim that waters off Taiwan’s east coast are also within its law-enforcement jurisdiction,” Koo told reporters before a meeting of the island’s legislature, saying this seriously harmed Taiwan’s rights.

Koo said Taiwan’s defence ministry and coastguard would coordinate to safeguard the island’s maritime security.