LISBON - All African heads of state, including Zimbabwe's Robert Mugabe, will attend a long-delayed EU-Africa summit in Portugal later this year, African Union president Ghana said on Wednesday.

Mugabe and more than 100 other Zimbabwean officials are banned from travelling to EU nations under sanctions imposed in 2002, a restriction that threatens to derail an EU-Africa summit scheduled for December in Lisbon.

The AU said it would be unfair not to invite Mugabe despite widespread criticism in Europe over alleged human rights abuses and the possibility that British Prime Minister Gordon Brown would not attend.

"It would not be fair not to invite a member of the African Union," said Akwasi Osei Adjei, Ghana's Foreign Affairs Minister. Ghana currently holds the chair of the AU.

"I believe we are coming with all the members of the African Union, the heads of state of the African Union," he said. "So, definitely the invitation will be issued (to Mugabe)."

Summit plans have been on hold since 2003 as Britain and other EU states have refused to attend if Mugabe did. EU president Portugal has been seeking a compromise but has so far sent no invitations.

Osei Adjei's comments appear to be the first by an AU official stating clearly that Mugabe will come to the long-delayed summit.

Asked about the issue, Portuguese Foreign Minister, Luis Amado, whose country holds the rotating EU presidency, said: "Certainly the problem of participation is always (a problem) to consider." He did not elaborate.

South Africa and other African nations insist that Mugabe be allowed to attend the summit. European Union officials have suggested that Zimbabwe be represented at a lower level than Mugabe at the meeting, the first in seven years.

Osei Adjei urged Brown and Mugabe to resolve their differences to make the summit a success.

"I have seen somewhere that the British prime minister is saying that if the president of Zimbabwe comes he may not come," Osei Adjei said. "And I am saying to them: Why don't you use the diplomatic means to resolve whatever problems there are."

"We don't want a situation whereby certain issues drag the important issues that we are going to discuss."

The issue of the 83-year-old Zimbabwean leader, who has vowed to run for another term as president next year, is the main reason the European Union and Africa have not held a summit since their first effort in Cairo seven years ago.

Mugabe blames Western sanctions for hyper-inflation, food shortages and a spiralling economic crisis. Critics say Mugabe has destroyed the economy with his policy of taking over white-owned farms.