Amelia French says the move has again brought Congo into conflict with the aid agencies.
The relationship between the United Nations and the government of Laurent Kabila in Kinshasa took another turn for the worse over the weekend with the demand that all refugee organisations should leave the east of the country.
Pierre Gerety, director of the United Nations High Commission for Refugees (UNHCR) for the Great Lakes region, said that the decision followed the UNHCR's suspension last month of its work with Rwandan Hutu refugees in Congo-Zaire after the authorities there forcibly repatriated a number of Rwandan Hutus to Rwanda.
Over a million Hutus fled Rwanda in 1994 in fear of reprisals for the Hutu-led slaughter of around 800,000 Tutsi and Hutu opponents to the former regime. The great majority have now been repatriated to Rwanda. But some are believed to be reluctant to emerge from the forests and remote villages of eastern Congo-Zaire.
The Rwanda authorities say these people do not want to return because they know they will have to face justice if they participated in the genocide.
Mr Gerety acknowledged that Hutu militiamen - many of them members of the former government army which played a leading role in the genocide - were still present in Congo-Zaire. "The UNHCR has been faced with the very difficult problem of distinguishing between innocent people and military elements and perpetrators of the genocide. This remains a thorny issue," he said.
The UNHCR has been strongly criticised, especially by the Rwandan government, for allowing the militiamen to rearm, train and recruit in the refugee camps it set up along the border. It seems that it was the fear that this would happen again that contributed to the Congolese decision to expel the UNHCR.
Last week, several hundred Rwandan Hutus fled across the border from the north-western region of Gisenyi into the Goma area, ostensibly to escape heavy fighting. The Rwandan military commander for the northwest, Colonel Kayumba Hyamwasa, said at the weekend that this group had been lured across the border by militiamen who launch attacks from there against military and civilian targets in northwest Rwanda. Col Kayumba said their intention had been to prompt the UNHCR into setting up another refugee camp. It would appear that the Rwandan and Congolese governments decided together that this should not happen.
The Rwandan government has also taken further preventive action. Col Kayumba said that all the civilians who fled had been repatriated, along with no fewer than 1,000 militiamen rounded up by the Congolese security forces - the first time the security forces on both sides of the border have openly cooperated.