Kuwait's Emiri Diwan said in a statement on Thursday that the ruling Emir Sheikh Sabah al-Ahmad al-Sabah's health is stable and that the Emir is receiving the scheduled medical treatment following surgery, the state news agency cited the Diwan statement.
Al-Sabah is currently in the United States after flying there last month to receive treatment.
The Kuwaiti emir authorized his crown prince to temporarily take over some responsibilities in the meantime.
The 91-year-old emir has ruled the US ally and OPEC oil producer since 2006 and steered its foreign policy for more than 50 years.
In October of last year, Sheikh Sabah had suffered a health setback while in Kuwait and was admitted to a hospital in the United States during his trip for a meeting with US President Donald Trump.
After receiving treatment, the emir then returned to Kuwait.