Nairobi - The United States has followed through on a threat to place travel bans on top Kenyan officials, announcing Monday that one senior figure has had his visa revoked and that another three are expected to receive similar treatment.

Speaking in Nairobi, Johnnie Carson, Assistant Secretary of State for African Affairs, said the unnamed senior government official had obstructed justice and failed to tackle rampant corruption in the East African nation.

The US is ramping up the pressure on the country' leaders for failing to bring to justice those accused of the violence that followed 2007's disputed presidential elections.

Estimates say upward of 1,300 people died in the violence, but Kenya has failed to set up a local tribunal to try suspects, as recommended by an independent commission.

The International Criminal Court in The Hague is in possession of an envelope containing the names of politicians and businessmen accused of orchestrating the violence, and is expected to step in if Kenya fails to act.

Two independent commissions recommended a raft of changes in areas such as the police, the judiciary and land policy, but the reform process has been moving at a snail's pace.

Corruption is also rife in East Africa' largest economy, but no high-ranking officials have been brought to book despite several massive scams to steal public money in recent years.

US Ambassador to Kenya Michael Ranneberger last month said that 15 ministers, members of parliament, permanent secretaries and other officials had received letters saying that their "future relationship" with the US was dependent on support of reform and "opposition to the use of violence."(dpa)