An interbank borrowing rate of 26 percent in Kenya is unacceptable, a senior Treasury official said on Friday, and staff from the ministry of finance and the central bank are working on a plan to deal with interest rates while supporting the shilling currency.

"The interbank rate has gone up pretty high. That is not good for the economy because it means interest rates can rise sharply. At 26 percent, that is unacceptable," Geoffrey Mwau, economic secretary at the Treasury, told Reuters.

"We have our staff now working on recommendations that we will look at by Monday, Tuesday. Whatever we come up with, we implement. There are actions we can actually take to bring the (exchange) rate down. After our staff meet, those are the things that we will be dealing with, both the shilling and interest rates."