Former prime minister Dr Mahathir Mohamad should not be speaking on matters that he cannot appreciate, said Johor Menteri Besar Mohamed Khaled Nordin.

Khaled said this in reference to Mahathir's warning that state nationalism, including in Johor, could lead to the collapse of the Malaysian federation.

"To Mahathir, there is no need for him to speak and comment on matters not in his field of expertise. It is something that he cannot appreciate," he said in a statement today.

Khaled said that contrary to Mahathir's assertion, Johor nationalism would help strengthen the federation.

"The rise of Johor nationalism does not in any way seek to separate from the Malaysian federation.

"Strong states, with a strong society, will form a strong federation," he said.

Khaled said Johor nationalism was about unity that would bring people together, regardless of race and religion based on harmony, mutual understanding and tolerance.

He added that the concept of "Bangsa Johor" had long existed in Johor, since 1920, before the formation of the federation.

He added that others should also emulate the rise of Johor nationalism.

He also gave his assurance that Johor would continue to maintain a good relationship with the federal government.