Washington and its NATO allies were looking into giving Macedonia more military aid - but not troops - to help end an ethnic Albanian rebellion on its doorstep, the US State Department has said.
"We are certainly, within NATO, considering what we can do to help them militarily," State Department spokesman Mr Richard Boucher told a news briefing.
Asked if this included "hardware", he replied: "Yes, hardware, logistics, expertise, more information-sharing. There are a variety of ways of helping people without putting our troops in, necessarily".
The Albanian rebels have been given until midnight to withdraw, surrender, or face a Macedonian army onslaught to oust them from hills around the city of Tetovo.
President Bush, speaking to reporters during a visit to CIA headquarters in Langley, Virginia, repeated the US position, saying Washington was very much involved in the NATO process.
"We'll work with the Macedonian government to help Macedonia protect its own borders," Mr Bush said.
Mr Boucher offered no details of what "hardware" was being considered and said he was unaware of any requests for US or NATO forces to enter Macedonia, which has been pounding rebel positions near the border with Kosovo - which has an Albanian majority - for six days.
NATO Secretary-General Lord Robertson has promised decisive action to strengthen the border but has not specified troop numbers, locations or timing.
He said the idea was to cut off the rebels' supply routes but that the international community would not seek an extended mandate to operate within Macedonia.
British Prime Minister Mr Tony Blair has expressed concern about the escalating violence in Macedonia.
Mr Blair discussed Macedonia and other issues with Greek Prime Minister Costas Simitis during a two-hour meeting in London last night.
Yesterday Britain's Defence Ministry said it was sending a military team to Macedonia to advise the Balkan state in its battle against ethnic Albanian rebels.