SEOUL, March 31 (Reuters) - Korean Air will enter emergency management mode from April as rising oil prices driven by the war in the Middle East weigh on costs, a source with knowledge of the matter told Reuters on Tuesday.

The airline said in an internal memo reviewed by Reuters that if high oil prices persist, it expects significant disruption to its annual business targets, and will shift to an emergency operating system from April.

The memo added that the airline plans to implement phased response measures based on oil price levels, and step up company-wide cost efficiency to offset surging fuel costs.

(Reporting by Heejin Kim and Heekyong Yang; Editing by Christian Schmollinger)