Tlakula, who is also Independent Electoral Commission chief electoral officer, made the appeal after receiving reports of Gambia's crackdown on the media. She said the bid to silence the state's critics, including a recent swoop on journalists, flagged the deterioration of freedom of expression in Gambia.
Jammeh is accused of threatening to arrest the Imam of Kalifing, Baba Leigh, an outspoken critic of the government. He demanded that Leigh and media practitioners desist from "publicly criticising" his presidency or face jail.
The National Intelligence Agency has arrested seven leaders of the Gambian Press Union.
Several other journalists disappeared weeks ago.
Tlakula said that if the reports were accurate the Gambian government "would be failing in its obligations to protect the right to freedom of expression" as reflected in article 9 of the African Charter on Human and Peoples' Rights of the African Charter.