Chinese Foreign Minister Wang Yi on Sunday asked Malaysia to continue search for a missing Malaysia Airlines passenger jet with 239 people on board.

Every minute counts as the plane has lost contact for about 40 hours, Wang told his Malaysian counterpart, Anifah Aman, in a telephone conversation. Search and rescue should not stop so long as there is a glimmer of hope, he said.

He asked Malaysia to inform the Chinese side of any developments without delay.

Wang requested help and cooperation from Malaysia as China's rescue ships are heading for the related sea waters.

The Chinese government and people attach great importance to the issue, Wang said. Chinese President Xi Jinping has given important instructions over the issue, and Chinese Premier Li Keqiang had an emergency telephone conversation with his Malaysian counterpart, Najib Razak, on Saturday, Wang said.

Anifah said that Malaysia is sparing no effort in search for the missing aircraft and will keep close communication and coordination with China.

Wang also talked over the phone on Sunday with Vietnamese Vice Prime Minister and Foreign Minister Pham Binh Minh. He expressed the hope that the Vietnamese side will assist the Chinese side in continuing exerting all efforts for launching search and rescue operations.