Outgoing Colombian President Gustavo Petro (shown) has barred President-elect Abelardo De la Espriella from holding his inauguration at a military base. Photo by Aris Mariota/EPA

July 13 (UPI) -- Outgoing Colombian President Gustavo Petro has barred President-elect Abelardo De la Espriella from holding his inauguration at a military base, triggering an unprecedented institutional dispute that has clouded the transfer of power and underscored the country's deep political polarization.

Citing his authority as commander-in-chief of the armed forces until Aug. 7, the leftist president blocked De la Espriella's plan to take the oath of office before military personnel.

The incoming government had sought to use the ceremony to signal a sharp break with the outgoing administration's security policies.

"Military and police barracks are under my command until the new president is sworn in and, therefore, until that moment I am the supreme commander of the military forces," Petro wrote on X.