Updated

In its latest personal attack on a prominent official from a rival country, North Korea on Wednesday called U.S. Secretary of State John Kerry a wolf with a "hideous lantern jaw."

North Korea has unleashed a slew of crude insults against leaders in Washington and Seoul this year, calling President Barack Obama a monkey and South Korean President Park Geun-hye a prostitute.

Wednesday's slur against Kerry appeared only in a Korean-language dispatch, suggesting it was meant to rally anti-U.S. sentiment and burnish the leadership's image domestically at a time when Washington and Seoul are conducting annual military drills that Pyongyang calls an invasion rehearsal.

An unidentified policy department spokesman at the North Korean defense commission, led by leader Kim Jong Un, described Kerry as a "wolf donning the mask of sheep."

The spokesman criticized Kerry for recently saying Washington wants to see peace on the Korean Peninsula although the U.S. and South Korea then went ahead with their summertime drills that North Korea has demanded be scrapped. The U.S. and South Korea say the drills are defensive in nature.

The North Korean spokesman also criticized Kerry's comments on North Korea's human rights record and weapons programs.

"His behavior fully revealed once again the U.S. inveterate nature as a hypocrite who has deceived and mocked mankind with all sorts of gimmicks," the spokesman said in a statement carried by the official Korean Central News Agency.

South Korean and U.S. officials often criticize the North's invectives but stop short of similar rhetoric against North Korean leaders. But conservative activists in South Korea frequently use images depicting North Korean leader Kim Jong Un as a pig in anti-Pyongyang rallies.

Tension on the Korean Peninsula remains high as North Korea has conducted an unusually large number of missile and artillery test firings this year.