ZenFone, priced as low as US$99, has been sold in 11 countries, including Taiwan, China, Indonesia, Vietnam, Malaysia and Thailand.
The phone is still facing supply shortages in each of those markets due to strong demand despite a monthly production capacity of 1 million units, Shen said.
The company plans to launch ZenFone in yet another market -- Brazil -- in October, he added.
Asustek aims to sell 7.5 million smartphones in 2014, a figure that is five times the 1.5 million units shipped last year, according to Shen.
