Ghana has taken steps needed to address revenue shortfalls and consolidate debt, both critical measures in addressing the West African country's fiscal challenges, Finance Minister Seth Terkper said on Friday.

In reaction to Moody's Ghana downgrade on Thursday, Terkper said the economy has strong medium term prospects and the government will ensure these are not derailed by fiscal shocks such as the recent low oil prices.

Moody's Investors Service downgraded Ghana's sovereign rating and put the country on a negative outlook to reflect an increasing debt burden, large fiscal imbalances and a sharp weakening of the cedi currency.

The downgrade is a further blow to the economic reputation of the West African country, which for years saw strong growth rates due to its exports of gold, cocoa and oil but faces a raft of macroeconomic problems.

"The key element of what we are doing is to address the revenue shortfalls, ensure the achievement of the objectives of the ongoing fiscal consolidation, and keep borrowing in line with approved levels. We have also cleared most of the arrears and we are removing subsidies," he told Reuters.

Terkper said the country's medium-term prospects remained bright, underpinned by expected additional oil and gas production, enhanced services sector performance and improvements in agriculture.

Analysts fear the Moody's downgrade could further push already high interest rates up and increase volatility of the local currency which is already down nine percent since January.