The Democratic People's Republic of Korea (DPRK) said on Sunday nuclear issues will not be discussed when talks with the United States restart unless the withdrawal of U.S. "hostile policy" was put on the agenda, state media reported. 

The North's foreign ministry said in a statement carried by the official KCNA news agency that the recent passage of a United Nations resolution on Pyongyang's human rights was a U.S.-led "political provocation." 

The DPRK has previously described the U.N. criticism as a product of U.S. "hostile policy". 

Meanwhile, the DPRK leader Kim Jong Un attended a military air show at Wonsan Kalma Airport on the North's east coast. 

After watching the show, Kim urged all pilots to be "fully ready for effectively applying" air tactics to operations and battles, adding it is important for them "to possess high level of aviation, bombing skill and marksmanship by systematically conducting flight drills on a normal basis under the simulated conditions of an actual war in the severest condition." 

"Our pilots have to try to fight the enemies armed to the teeth with great idea and tactics under any circumstances," Kim was quoted as saying. 

The U.S. and the Republic of Korea (ROK) announced on Sunday they will postpone upcoming military drills in an effort to bolster a stalled peace push with the DPRK. 

"I don't see this as a concession. I see this as a good faith effort... to enable peace," US Defense Secretary Mark Esper said, as he announced the decision standing alongside his ROK counterpart in Bangkok. 

Japanese Defence Minister Taro Kono told his U.S. and ROK counterparts on Sunday that "no one could be optimistic about North Korea (DPRK)," shortly after Washington and Seoul's decision. 

"No one could be optimistic about North Korea (DPRK). North Korea (DPRK) has repeatedly launched more than 20 missiles this year, including new types of ballistic missiles, as well as a submarine-launched ballistic missile," Kono said at the opening of a so-called "trilateral" meeting of the defense chiefs in Bangkok, before news media were escorted from the room. 

(With inputs from Reuters)