THE aircraft in which the US Commerce Secretary, Mr Ron Brown, was travelling with 32 others crashed on a hilltop in bad weather as it approached the Croatian port city of Dubrovnik yesterday.
The Pentagon said it had no reports of fatalities or survivors, but President Jacques Chirac of France and the Croatian Foreign Minister, Mr Mate Granic sent messages of condolence for Mr Brown.
The Commerce Secretary was the main architect of President Clinton's programme of economic support for the Northern Ireland peace process. The President Mrs Robinson, said she had I learned of the accident with great shock and dismay and felt a deep sense of personal loss at Mr Brown's death.
The Tanaiste, Mr Spring, the Northern Secretary, Sir Patrick Mayhew, and the Fianna Fail leader, Mr Bertie Ahern, also paid tribute to Mr Brown.
The bodies of four occupants of the aircraft were found at night fall, Croatian officials said.
The Croatian Prime Minister, Mr Zlatko Matesa, said one survivor, a woman, was found in the wreckage of the US Air Force T43, a military version of the Boeing 737. A doctor at Dubrovnik Hospital said that the survivor died en route to the hospital.
US officials said they did not believe the US military plane, which carried 27 passengers and a crew of six, had been attacked by any of the warring factions in the former Yugoslavia.
"There were no calls indicating any problem at all aboard the aircraft," Lieut Gen Howell Estes said at a news conference at the Pentagon. But bad weather had forced the pilot to try to make an instrument landing at the Dubrovnik airport, he said.
French and US helicopters searched for wreckage, but as darkness fell, they were forced stop their efforts.
President Clinton expressed grief for the victims and praised Mr Brown, while at the same time suggesting he was not certain about the Secretary's fate. "We do not know for sure what happened," he told employees of the Commerce Department.
The Pentagon, which has a significant presence in the Balkans including 20,000 troops in Bosnia, was working to piece together what had happened.
Mr Brown was on the first leg of a two day trip to Bosnia and Croatia to boost trade and aid reconstruction. He had been in Bosnia with chief executives from some 12 US businesses.
Mr Brown (54), a lawyer and one time chairman of the Democratic Party, became the first US Administration figure to visit Belfast on official business when he led the US delegation to Mr John Major's investment conference in December 1994.
President Clinton's decision to dispatch Mr Brown, one of his foremost policy makers, was seen as a powerful commitment to the Northern Ireland peace process. When the President then announced his own investment conference in Washington last May, the Commerce Secretary was charged with developing the strategy of US economic support for Ireland.
Mr Spring last night described Mr Brown a personal friend and a great friend of the peace process. Sir Patrick said he was hugely impressed by his friendship for the people of Northern Ireland and everyone on this island.