Relations between the two countries came under severe strain

Mr Uribe had been due to meet Venezuelan President Hugo Chavez on Thursday to resolve a diplomatic row.

But Colombian officials said he would now be unable to travel to Caracas or to visit Spain, France and Belgium.

Venezuela froze links with Colombia after it admitting paying bounty hunters who had captured a rebel chief

on Venezuelan soil.

Mr Chavez has said the dispute was one of the most serious in decades.

He says he regards the dispute as "practically over", but that any final conclusion will depend on their discussions which he expects to be "frank".

In late January, the Colombian leadership issued a statement assuring Venezuela the incident would not be repeated and saying that the matter had been resolved.

Viral infection

Colombian officials said Mr Uribe was suffering from labyrinthitis - an inflammation of the ear canal that helps control balance.

The condition is normally the result of a viral infection and causes dizziness.

The officials said Mr Uribe had also suffered gastro-intestinal symptoms.

The Colombian foreign ministry said Mr Uribe was unable to travel and would visit the countries concerned at a later date.

The Colombian president had been due to begin a five-day European tour on Monday which would have included meetings with leading politicians, heads of state and officials in Madrid, Paris and Brussels.

Severed ties

The dispute with Venezuela arose after Colombia admitted that it paid bounty hunters who had captured a Colombian Marxist rebel leader in Caracas.

Rodrigo Granda, a commander in Colombia's largest left-wing rebel group, the Revolutionary Armed Forces of Colombia (Farc), was kidnapped in Caracas in mid-December.

Venezuela - which blames the US for provoking the crisis - accused Colombia of violating its national sovereignty and demanded an apology.

Colombia paid mercenaries to capture Granda

It also severed both diplomatic and business ties - worth an estimated $1.7bn (�900m) last year.

A $200m natural gas pipeline project between the two countries was one of the casualties of the dispute.

Oil-producing Venezuela is Colombia's second-largest export market.

Venezuela also withdrew its ambassador from the Colombian capital, Bogota - a gesture not reciprocated by Colombia.