Story highlights Gillian Milovanovic is the first U.S. chair of the U.N.- backed Kimberley Process

Milovanovic says the definition of blood diamonds will 'certainly be looked at'

Last year, founding member Global Witness pulled out of the process

The move followed the sale of diamonds from Zimbabwe's controversial Marange fields

The newly-appointed U.S. chair of the international diamond watchdog has called for a review of what constitutes a "blood diamond."

According to the Kimberley Process, launched in 2003 to certify that diamonds do not come from conflict zones, blood diamonds are rough diamonds used by rebel movements or their allies to finance armed conflicts aimed at undermining legitimate governments.

Now, Gillian Milovanovic, who was named chair of the Kimberley Process in late January, wants the definition to be broadened. "One of the things which will certainly be looked at and which we certainly support looking at and believe should get a close look is whether that definition is still sufficiently encompassing or appropriate given today's challenges," she said in an exclusive interview with CNN's Robyn Curnow.

Milovanovic's chairmanship comes at a challenging time for the scheme, following the fallout from its decision last year to allow Robert Mugabe's Zimbabwe to sell diamonds from its controversial Marange fields.

The move was criticized by activists and led to Global Witness, one of the initiative's founding members, to pull out of the process in December, saying the diamond regulatory group had refused "to evolve and address the clear links between diamonds, violence and tyranny."

An edited version of Milovanovic's interview follows.

CNN: Is the Kimberley Process in crisis?

Gillian Milovanovic: No, I do not believe so. In fact, I'm very pleased to have an opportunity to be the chair at this time because we are essentially on the eve of the 10th anniversary of the Process.

CNN: Global Witness, one of the founding members, has pulled out -- they said it was because they were shocked that the Kimberley Process had authorized sales of diamonds from Marange fields in Zimbabwe. What's your reaction to that?

GM: Obviously we're very sorry that that was the decision that Global Witness took, they were one of the founding members of the process -- unfortunate, sad development but the bridges are not cut as far as we are concerned and certainly I intend to talk with everyone.

CNN: Their decision came after the authorization of diamond sales from Zimbabwe, very controversial fields in Marange.

GM: Well certainly for two years the Kimberley Process labored to find a solution to how to handle the diamonds from Marange -- November of last year the process made a decision, the United States deliberately chose to abstain in order to allow the process to continue and in order to move forward.

Now that said, I think that for our chairmanship the experience of the difficulties that we're experiencing in finding a solution for the Marange diamonds are an impetus to looking at how well the Kimberley Process is situated to deal with today's challenges.

CNN: From the U.S. perspective, you said you've abstained from that decision, why has the U.S. particularly imposed sanctions against one of the companies operating in Marange?

GM: The United States, on a bilateral basis of course, has sanctions against Zimbabwean identified entities. Essentially these are imposed because these entities are undermining democracy and democratic institutions.

And it happens that some entities which are designated by our process as having to do with undermining democracy are in fact 50 per cent or more shareholders in diamond mines in Marange and hence the link between the two things.

CNN: There is a sense of contradiction here -- why didn't you veto it, particularly because the U.S. has sanctions against some companies in the Zimbabwean diamond fields.

GM: But there is also, one could argue, a similar situation in the fact that the Kimberley Process indeed made a decision by consensus, minus us, that to certify diamonds from a number of mines, whereas those same diamonds cannot be imported into the United States, that is the situation.

With respect to my own chairmanship, I have been asked to be the chair and therefore my role as I see it is to give impetus, to show leadership but to understand that it is the organization that is ultimately going to be responsible for the decisions that are made.

CNN: Do you see the definition of a blood diamond being widened?

GM: A diamond. the proceeds of which are used by illicit guerrilla or rebel entities trying to overthrow a legitimate government, that was the basis on which the organization was founded. One of the things which will certainly be looked at and which we certainly support looking at and believe should get a close look is whether that definition is still sufficiently encompassing or appropriate given today's challenges.

CNN: How can you be sure as a consumer that the diamonds that you have on your finger are not being used to finance a corrupt or conflict scenario?

GM: I think that it's important that the consumers do understand that it's not a conflict diamond in the sense of the definition which exists, mainly the guerrillas are not using the money from this to conduct bloody wars to overthrow a legitimate government.

Now, if one is looking for something beyond that as a consumer that is the kind of question that one needs to address to the person who is selling the diamond.