Khaled al-Asousi, KNPC's deputy chief executive for support services, gave the updated figures in a message to Reuters. On Sunday, refinery production was around 520,000 bpd, down from 930,000 bpd before the strike began.
Thousands of Kuwaiti oil and gas workers are striking to protest against a government plan for public sector pay reforms, although non-Kuwaiti workers in the industry are not on strike. Unions have not said how long the walkout will last.
Kuwait Oil Co spokesman Saad Al-Azmi said on Sunday that his company had cut crude oil output to 1.1 million bpd from its normal level of about 3 million bpd. On Monday, officials had not yet given an update on the crude production level.