He hinted that diplomatic relations were hanging upon Libya keeping its word and making further payments to the families of the 170 victims of the bombing of a French plane over Niger.
"I don't want to imagine that these promises won't be adhered to. If by chance they were not, it would not be possible for that to not have consequences for relations" between France and Libya, said Chirac on Saturday.
"I say this without aggression, but without weakness," added the French president, who delivered his warning at a news conference during a visit to Morocco.
Under an earlier preliminary agreement, Libya and negotiators for families of those killed in the bombing were meant to have reached a definitive deal on compensation by Saturday.
But Francoise Rudetzki, one of those involved in the talks, told news agency AP that negotiations were stalled. She said she hoped that Chirac's comments would prompt Libya into action.
"We're still waiting for a sign from Libya," she said.
Abderaman Koulam Allah, whose sister and five of her children were killed in the attack, said "France should take severe diplomatic measures" against Libya.
The earlier partial deal, signed on 10 September, cleared the way for a United Nations vote that lifted 11-year-old sanctions against Libya.
Libya has proposed $1 million for each family of the people killed in the bombing of the French UTA airline DC-10 over Niger, but the sum is still too low, said a spokesman in France for the families, Guillaume Denoix de Saint Marc.
"It is not possible that Libya could come back into the court of nations having killed 170 people and not having resolved the problem"
Guillaume Denoix de Saint Marc,
spokesman for the families
He said he remained convinced, however, that a solution would be found. He said he believed that Libya's failure to meet the Saturday deadline for a definitive compensation deal was due to organisational problems on its part, not a change of heart.
"It is not possible that Libya could come back into the court of nations having killed 170 people and not having resolved the problem," said Denoix de Saint Marc, whose father was killed in the bombing.
A French court has convicted the brother-in-law of Libyan leader Colonel Muammar Qadhafi and five other Libyans in absentia and sentenced them to life in prison in 1999 for the bombing. They remain at large.
The extra compensation being sought by victims' families would be a follow-up to the $33 million Libya has already paid in the case.
But families, backed by the French government, demanded that Libya should give more money after it agreed to pay far higher compensation - $2.7 billion - to relatives of the 270 victims of the 1988 downing of a Pan Am jet over Lockerbie, Scotland.