Afghan President Hamid Karzai is postponing a trip to Pakistan in order to deal with election issues at home, but will reschedule the visit shortly.

President Karzai's aides say the delay is meant to allow the Afghan leader to take care of last-minute issues involving his application to run in the country's presidential election, scheduled for October 9.

Monday is the deadline for candidates to register.

A spokesman for the president's office denied reports that the delay was connected to a dispute over whom Mr. Karzai would chose as his running mate.

The spokesman said the president's running mate would be announced sometime in the coming week.

In an interview with VOA Friday, President Karzai said the main focus of his planned meeting with Pakistani President Pervez Musharraf would be cooperation on flushing out militants staging attacks across Afghanistan.

Afghanistan suffers from an armed anti-government insurgency, with militants regularly staging attacks on military and civilian targets.

Many of the insurgents are believed to have bases inside Pakistan's semi-autonomous tribal area, and Paksitani troops have conducted a series of operations during the past year to track down the suspected militants.

While Mr. Karzai and other Afghan officials have praised these operations, the U.N. refugee agency said Sunday it is concerned over the effect on refugees living in the area.

"The security situation in the tribal areas over the past few months, has compelled about 20,000 Afghan refugees, we believe, to return to Afghanistan under less than ideal circumstances," said Paul Stromberg, a repatriation coordinator for the United Nations High Commissioner for Refugees.

He cited cases in which fighting between Pakistani paramilitary troops and suspected militants had forced refugees to flee back to Afghanistan against their will and under very short notice.

Mr. Stromberg said, while the United Nations understands the need for Pakistan's military operations, more must be done to insure the impact on innocent Afghan refugees is limited.