The son of Libyan leader Moammar Gadhafi said he believed the case could be resolved soon, but warned that the demands of the victim's families must be met.

"In a marathon it is often the last mile that is the most difficult," Seif al-Islam Gadhafi, Gadhafi's son and the head of the Kadhafi Foundation which has been involved in the negotiations, told AFP.

The five Bulgarian nurses and a Palestinian doctor have been held in a Libyan prison for more than eight years. The medics stand accused of infecting 438 children with tainted blood at a Benghazi hospital. Fifty-six children have since died.

The medics were sentenced to death in May 2004. They maintain their innocence, saying they were tortured into confessing.

Top EU officials visit Libya

Steinmeier visited a hospital with HIV-infected children Monday.

"Today's visit to this hospital moved me deeply. I admire the strength and courage with which everyone involved - doctors, nurses and parents - are helping the children by easing their suffering," Steinmeier said, according to a German Foreign Ministry statement.

Steinmeier said the EU wanted provide the children with the world's most modern AIDS treatment.

"We have a deep moral obligation to help these children," said Steinmeier, who was due to return to Berlin on Monday evening.

Steinmeier also visited the Bulgarian nurses Monday.

"We are not abandoning the six prisoners. They can count on our support. Europe remains on their side," Steinmeier reportedly said after the meeting.

He was accompanied to Libya by EU Commissioner for External Relations Benita Ferrero-Waldner. On Monday, Ferrero-Waldner said she saw "a window of opportunity" for a resolution to the dispute.

During a Monday visit to Bulgaria, United States President George W. Bush said the nurses should be set free.

"We strongly support the release of the Bulgarian nurses in Libya," Bush told a news conference in Sofia. "It's a high priority for our country."

"Together with the EU, the United States is contributing to a fund to provide assistance to the Libyan children suffering from this disease (HIV/AIDS) and to their families," Bush said.

Libya demands money for families of victims

Libya has said the families should be compensated. Tripoli has demanded 10 million euros ($13 million) for each child's family. Bulgaria has rejected this, saying it would be an admission of guilt. There has been an offer to treat the children at European hospitals.

Steinmeier and Ferrero-Waldner met with Gadhafi Sunday.

"I hope that this case will be resolved soon, particularly if the demands of the (victims') families are met," Gadhafi said Sunday.

Last month, al-Islam said he hoped the case could be resolved following talks between representatives of the families and the international community which were held May 10 in Brussels.

EU wants speedy resolution

Idriss Lagha, chairman of the Association for the Families of the HIV-Infected Children, said he wanted to reach an agreement on the case before June 21. Lagha is the father of one of the HIV-infected children and is a negotiator seeking settlement of the case.

Lagha said Steinmeier and Ferrero-Waldner want to find a speedy resolution to the crisis and voiced support for an EU offer of medical treatment for the children, Reuters reported.

"We also discussed the issue of compensation, but this is still under negotiation," Lagha told Reuters.

The death sentence for the nurses and Palestinian doctor was upheld last December. They are still awaiting the result of an appeal.