KARACHI, April 23: A senior US congressman who is highly critical of the Afghan government has been prevented from entering the country, a BBC report quoted Afghan officials as saying.

The officials said that Dana Rohrabacher had been refused a visa and was prevented from boarding a flight to Afghanistan from Dubai.

The congressman has criticised the Kabul government for alleged corruption and Afghan officials accuse him of undermining national unity.

Analysts say the incident highlights the volatility of USAfghan relations.

According to the BBC correspondent in Kabul, this comes at a particularly sensitive time, ahead of a summit in Chicago next month on the future of the country.

The congressman was stopped in Dubai on Friday as he was leading a delegation to Kabul. Officials say that while other members of the delegation had visas for Afghanistan, Mr Rohrabacher did not.

US Secretary of State Hillary Clinton was reported to have conveyed a message from President Hamid Karzai to the congressman that he would not be welcome in the country.

Mr Rohrabacher, who is chairman of the house foreign affairs subcommittee, has frequently called for a more decentralised form of government in Afghanistan as well as a US investigation into alleged government corruption.

Afghan officials said that in addition to his criticism of the president, Mr Rohrabacher was being shunned because of meetings he had held in Berlin with Afghan politicians about the creation of a decentralised form of government. Afghan officials reportedly view that as an interference in the country`s internal affairs.

`Anyone who speaks against the good of Afghanistan and tries to interfere in our internal affairs is ineligible for an Afghan visa,` said one official.

The American embassy in Kabul has been quick to distance the US government from Mr Rohrabacher, whose involvement in Afghanistan goesback to the1980s during the Soviet invasion of Afghanistan. At the time he often accompanied Mujahideen fighting the Russians.-Dawn Monitor