Nairobi — President Obama's administration on Wednesday issued a strong warning to Kenya: Hasten key reforms or lose Washington's support.

In a terse letter, the US assistant secretary for African affairs, Mr Johnnie Carson, warned that it would not be "business as usual" with the government unless it speeds up reforms in key areas.

The letter expressed pessimism about the pace of reforms in the country and warned that future relations with the America will be linked directly to Kenya's commitment to implementing "urgent and clear" reforms.

"President Obama and Secretary Clinton have made clear their deep concerns that the key elements of the reform agenda have not been implemented. They have made clear that as a friend and a partner of Kenya, we want to help, but that you will not do business as usual with those who do not support reform or who support violence," the letter warned.

The letter seen by the Nation listed key reform areas the US wanted acted on as including the fight against corruption, an overhaul of the Judiciary, the police force and the Attorney General's office.

It also called for the speedy implementation of land reforms and the prosecution of perpetrators of post-election violence as well as the establishment of a permanent Electoral Commission.

The letter demonstrates Washington's growing impatience with the Kenya's government's slow pace in implementing major reforms in various sectors.

Prime Minister Raila Odinga was left out of a luncheon hosted by President Obama for heads of state and governments attending the 64th UN general assembly in New York, signaling America's growing impatience with the pace of reforms.