MANILA - President Rodrigo Duterte is "okay," Malacañang said Monday, after the chief executive revealed he was suffering from a chronic autoimmune neuromuscular disease and had "a very bad case of cold" following his week-long trip to Russia.

The 74-year-old leader was "up and about" when he met with Filipino reporters in Russia and complained about being unable to sleep on his flight back to Manila, said Presidential Spokesperson Salvador Panelo.

• Duterte says he has chronic neuromuscular disease

"Alam mo okay (He's okay). What he complained about was he was unable to sleep during the flight," Panelo told reporters when asked if the President was feeling well.

Duterte on Sunday told reporters he did not sleep throughout the 13-hour flight from Moscow to Manila.

"But anyway, talagang malamig kaya ako naka --- and I’m nursing a very bad case of a cold," he said.

A day before, Duterte said he had a condition called myasthenia gravis, which affects the muscles in his eyes.

"Narinig ko lang sa kanya kahapon eh (I heard it from him only yesterday). He didn’t elaborate on that," Panelo said.

Panelo told ANC's Headstart that he knew the President was suffering from a common illness of the elderly.

"Matagal nang meron ata siyang ano diba. Alam ko dati na, yung ordinaryong sakit ng matatanda meron siya," he said.

(I think he has it for a long time now. I know he has an ordinary sickness of the elderly.)

"Mukha namang hindi. Nakita mo naman ang schedule niya 'di ba? I’m even amazed how he survived this Russian trip. Sabi ko ibang klase rin to," he added when asked if the condition should be a cause for concern.

(There seems to be no need to worry. Have you seen his schedule? I’m even amazed how he survived this Russian trip. I said, he's one of a kind.)

"Sinisisi ko nga protocol bakit kayo ganyan? (I blame the protocol, why are you like this?). Even the President complains 'Papatayin niyo ba ko?' (Are you trying to kill me?)"