UPDATE 1-Kerry says U.S. wants to see N. Korea take steps for peace

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DOHA, March 5 (Reuters) - U.S. Secretary of State John Kerry said on Tuesday that Washington hoped North Korea would engage in negotiations to resolve world concerns instead of threatening to scrap a 50-year old truce with the South.

Pyongyang threatened on Tuesday to scrap the agreement that ended a 1950-53 civil war and sever a military "hotline" with the United States if South Korea and Washington pressed on with two-month-long war games.

"Rather than threaten to abrogate, the world would be better served if they (North Korea) would engage in legitimate dialogue," Kerry said on Tuesday during a joint new conference with his Qatari counterpart, Sheikh Hamad bin Jassim al-Thani.

"Our preference is not to brandish threats, but for peaceful negotiations," he added.

North Korea's threat was a notable sharpening in the country's often bellicose rhetoric and followed word that the United States and China had struck a tentative deal on a draft U.N. Security Council sanctions resolution that would punish North Korea for its third nuclear test, conducted last month.

The two Koreas remain technically at war since the 1950-53 conflict ended in an armistice rather than a peace treaty. (Reporting by Arshad Mohammed and Regan Doherty; Writing by Sami Aboudi; Editing by Tom Pfeiffer)