Inspector-general of police Khalid Abu Bakar said the force will wait "even if it takes five years" for the North Koreans suspects wanted for questioning in connection with the murder of Kim Jong-nam to come out of the embassy.

"We believe they are at the embassy compound, this includes the staff of Air Koryo, if they do not come forward, we will compel them to do so, before we issue a warrant of arrest," Khalid said at a press conference in Penang today.

"We will wait even if it takes five years, definitely someone will come out," he quipped.

Jong-nam is the North Korean leader's estranged half brother, who was believed to be murdered at KL International Airport 2 on Feb 13 by assassins using VX nerve agent.

According to Khalid, North Korean authorities were not cooperating with the investigations, saying he would seek Interpol's assistance if the situation persist.

Khalid denied that there were plans to raid the embassy for the suspects.

However, he confirmed that the police will compel them to come forward for questioning according to Section 111 of the Criminal Procedure Code.

As for the status of the second secretary, who may also be declared "persona non grata" by the Foreign Ministry, Khalid declined to comment.

"But we are following protocol and have written to the Attorney-General to compel him to cooperate with us," Khalid said.