Every minute counts as the plane has lost contact for about 40 hours, Xinhua quoted Wang telling his Malaysian counterpart, Anifah Aman, during a telephone conversation.
Search and rescue should not stop so long as there is a glimmer of hope, he added.
Wang has also 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.
The Malaysian foreign minister said his country was sparing no effort in search for the missing aircraft and would keep close communication and coordination with China.
Wang also discussed the plane crash with Vietnamese Vice Prime Minister and Foreign Minister Pham Binh Minh over phone, expressing the hope the Vietnamese side will assist the Chinese side in continuing exerting all efforts for launching search and rescue operations.
An international search and rescue mission from Malaysia, China, Singapore, Vietnam, the Philippines, Thailand and the US was mobilised with the sea mission. Search operations continued overnight and air mission resumed at daybreak Sunday.
The plane took off from Kuala Lumpur at 12.41 a.m. Saturday and was due to land in Beijing at 6.30 a.m. the same day. The 227 passengers on the flight included five Indians, 154 Chinese and 38 Malaysians.