"China is willing to work with relevant countries to find out the truth," foreign ministry spokeswoman Mao Ning told a regular briefing.

"Currently, China and Sweden are maintaining close communication on this issue," she added.

Sections of two telecom cables were cut on November 17 and 18 in Swedish territorial waters of the Baltic Sea off the coast of Denmark.

Suspicions have been directed at a Chinese ship -- the Yi Peng 3 -- which ship tracking sites said had sailed over the cables around the time they were cut, although there is nothing to indicate that it was involved in the incidents.

The Yi Peng 3 has remained anchored in the Kattegat strait between Sweden and Denmark since November 19.

"Sweden has... sent a formal request to China to cooperate with Swedish authorities in order to create clarity on what has happened. That formal request was sent to China earlier today," Prime Minister Ulf Kristersson told a press conference on Thursday.

Denmark's navy said last week it was shadowing the vessel, which is in international waters. Sweden's coast guard joined it over the weekend.