China National Offshore Oil Corp (CNOOC) said on Saturday it will enhance supervision and assistance to ConocoPhillips China (COPC) in handling the oil spills in north China's Bohai Bay to make sure that COPC fully implement maritime authority's requirements.

The statement came after the State Oceanic Administration (SOA) said COPC failed to meet its requirements of "screening out all potential sources for oil spills and blocking leaks once and for all" before the deadline of August 31.

The SOA on Friday ordered COPC cease all production operations on the leaking Penglai 19-3 oil field, which is jointly owned by COPC and CNOOC, China's largest offshore oil and gas producer.

CNOOC said it will urge COPC to work out plans to block the leaking sources as soon as possible. It also pledged to make its utmost efforts to assist COPC in better implementing the maritime authority's requirements.

The oil spill at the Penglai 19-3 oilfield, China's largest offshore oilfield, was first spotted in June. The oil has spread to beaches in Hebei and Liaoning provinces. The spills have been blamed for losses in the provinces' tourism and aquatic farming industries.

COPC, a subsidiary of US oil giant ConocoPhillips, is the operator of the Penglai 19-3 oilfield and owns a 49 percent stake. CNOOC has a 51 percent stake.