By David Ljunggren

OTTAWA (Reuters) - Canada said Tuesday Russia's campaign in rebel Chechnya

was on the verge of becoming a crime against humanity and suggested foreign

aid could be cut off if Moscow carried out its threat to destroy the region's

capital.

Foreign Minister Lloyd Axworthy said the West needed to put as much pressure

as possible on Russia to withdraw its ultimatum calling for all civilians to

leave Grozny by Saturday or face the prospect of obliteration.

Itar-Tass news agency said most people in the city were unaware of the

deadline set by Russian forces as part of their three-month campaign against

separatist Islamic forces. Up to 40,000 people are said to be trapped in

Grozny.

"I think the ultimatum they put to Grozny is unacceptable and it's really

getting to the point where it's crossing the line into potential crimes

against humanity," Axworthy told reporters after a cabinet meeting.

"You could have 30,000 people there -- very old, disabled, sick, who can't

move -- who are subject to major bombing and so I think it's very important

in the next couple of days that we try to put a restraint on that."

Canada has had trouble making its voice heard on Chechnya, in part because of

comments Axworthy made in late September on the need for Moscow to deal

forcefully with terrorist attacks. His words were replayed repeatedly on

Russian television.

Moscow, which was forced to stand by and watch NATO air attacks on its old

ally Yugoslavia earlier this year, has shrugged off foreign criticism of the

Chechen offensive.

Asked what the West could do to express its discontent, Axworthy said: "Well,

the Russians certainly have over the years been very reliant on Western aid."

British Foreign Minister Robin Cook warned Moscow that the European Union

could review financial and technical help if the attack on Grozny went ahead.

Axworthy said he would be writing to Russian Foreign Minister Igor Ivanov

later in the day to express Canada's concern.

"There will be an opportunity (for talks with the Russians) next week -- Mr

Ivanov will be at the Group of Eight foreign ministers' meeting in Berlin --

and will certainly be facing the music at that time," he said.

"I think what would be important now, in the next 24 or 36 hours, is to see

what can be done to halt or change, or restrain the Russian action as it

applies to the ultimatum which was given yesterday."

He also rejected the idea that the West's attacks on Kosovo had given Moscow

the right to do what it wanted in Chechnya.

"We went through that (the Kosovo campaign) after almost two years of active

discussions and negotiations. We haven't had the same run-up period (in

Chechnya)," he said.