"We have been a couple for 32 years. We have had a lot of experiences together. But she is the one who has to make the decisions ... it would be a big mistake if I interfered," Kirchner told local television.

Fernandez, who won 45 per cent of the vote against a divided opposition on October 28, now joins Michelle Bachelet, in neighboring Chile, as the second serving female president in Latin America.

Economic challenges

"We want Argentines to have hope again … while there is one poor person in the country, we will always be one step away from a definitive victory," Ferdandez said.

Her biggest challenge during her four-year term will be to ensure that the nation continues to recover economically by maintaining an annual growth rate above 8 per cent.

"We want Argentines to have hope again … while there is one poor person in the country, we will always be one step away from a definitive victory"

Cristina Fernandez de Kirchner, Argentine president
The new president has said she will aim to deal with inflation, corruption and energy shortages.
 
Around 10 percent of the population is unemployed and one quarter of the country's 39 million people are poor.

Kirchener said he was handing Fernandez a country that had returned to "nearly normal" from the 2001-2002 crisis, which saw a steep devaluation of the peso and a $100bn debt default.

Many of the left-leaning Latin American leaders who attended the ceremony, including Hugo Chavez, the Venezuelan president, Evo Morales, the Bolivian president and Rafael Correa of Ecuador see Fernandez as an ally.
 
"She's going to strengthen the process of change in the region," Chavez said.

She is unlikely to alter Kirchner's alliance with leaders such as Chavez, but she is seen as someone who could forge better ties with the next US president.
 
Fernandez refused to debate any of her rivals during the election campaign and has granted few interviews, preferring instead to be photographed overseas meeting world leaders.

Colombia hostages

The inauguration was marked by a flurry of diplomatic efforts to win the release of hostages held by Colombian rebels.
 
In her speech, Fernandez called for the release of Ingrid Betancourt, the Colombian presidential candidate who was kidnapped in 2002 by the Revolutionary Armed Forces of Colombia (Farc).

Al Jazeera's Lucia Newman in Buenos Aires said that there was great fear that Betancourt's health was so poor that she could possibly die within months.

"This has been going on for months and months but there is a feeling that the Columbian government, specifically the Colombia president has been dragging his feet looking for excuses not to come to some kind of negotiated settlement or exchange with the Farc guerillas," she said.

"But now, since the release just a few weeks ago of the proof of life of Ingrid Betancourt and some of the other hostages ... it's becoming far more urgent."

Several Latin American leaders appeared to be uniting at the ceremony to make a collective appeal for the hostages' release.