New Delhi, Oct 17 (IANS): Amid international economic uncertainty, Finance Minister Pranab Mukherjee Monday said he expectS India's GDP to grow by 8.5-9 percent in the medium to long-term period.

"In medium to long-term, India remains firmly on a high GDP growth path of 8.5-9 percent," Mukherje said while addressing the Asian Development Bank (ADB)-India partnership silver jubilee celebrations here.

Mukherjee, however, cautioned about the emerging economic challenges.

"We need to be alert and respond to emerging challenges and concerns, in a timely manner as we make efforts to achieve our potential as a young fast growing nation."

India's GDP grew at a slower rate of 7.7 percent in the first quarter of the current fiscal -- its weakest in the last six quarters.

Mukherjee cited food security and volatility in food prices as major challenges.

"We recognise that increase in agricultural production on a sustainable basis is the only long term solution to problem of availability as well as high and fluctuating food and commodity prices," he said.

Mukherjee added that infrastructure development was critical for productivity and to maintain growth.

"The 12th Five Year Plan (2012-17) has an ambitious target of infrastructure investment estimated at $1 trillion or nearly 10 percent of India's GDP."