Mauricio Macri celebrated his inauguration last week with a victory jig at the Casa Rosada presidential palace in Buenos Aires. But the time for dancing is over for Argentina’s new president. He must now fulfil his promise to fix a failing economy.

“Right now there is no sense of a climate of crisis. But the challenges they are inheriting are major, and there could even be some unpleasant surprises,” warned Miguel Kiguel, a local economist.

Mr Macri’s economic inheritance is “much more complex” than most Argentines realise, he says. Among the most urgent and delicate problems faced by the new government are the reserves at the central bank, which have fallen to “dangerously” low levels in order to prop up the overvalued peso, said Mr Kiguel.

Mr Macri’s campaign promise to remove strict exchange controls is ambitious because reserves will be needed to avoid an “overshooting” of the exchange rate, an inflationary spiral and an excessive rise in interest rates. Even so, Mr Kiguel argues that a devaluation is imminent, since the current situation is unsustainable.

A devaluation would help to trigger a huge influx of foreign exchange when Argentina’s farmers begin to sell between $3bn and $11bn of grain they are believed to be hoarding in the hope of a better exchange rate at which to sell.

This would also be helped along by a reduction of punitive taxes on grain exports, one of Mr Macri’s key campaign promises which is expected to be formalised soon.

The central bank’s new governor, Federico Sturzenegger — who took over after his much-criticised predecessor Alejandro Vanoli resigned on Wednesday under pressure from Mr Macri — is also hoping to bolster reserves by issuing a bond for as much as $10bn to a group of international banks including HSBC, JPMorgan, Goldman Sachs, Deutsche Bank and Citibank, according to the national newspaper La Nación.

Finance secretary Luis Caputo, a former executive at Deutsche Bank, has also taken the first steps to restart negotiations aimed at putting an end to a bitter legal dispute with a group of US hedge funds that has isolated the country from global capital markets since its $100bn sovereign debt default in 2001.

Another avenue being explored to provide support to central bank reserves is the renegotiation of a currency swap agreement with China.

Mr Macri’s surprise victory in Argentina has created optimism within the country and internationally that the nation’s long estrangement from global capital markets can be ended, according to Susan Segal, president of the Americas Society/Council of the Americas.

“This is a historic moment for Argentina,” she said.

But Mr Macri’s honeymoon will be short. The former mayor of Buenos Aires and his economic team must now assess the true extent of the economic damage they are inheriting, with long-discredited official statistics hiding the real size of the fiscal deficit, depleted foreign exchange reserves and an inflation rate which is already one of the highest in the world.

In addition to the immediate economic challenges facing the new administration are political and social challenges that could hinder reform attempts. Lacking a majority in congress to pass laws required to implement reforms, Mr Macri will need cross-party political support.

Mr Macri spent his first full day as president on Friday meeting the other candidates he defeated in the election, including Daniel Scioli and Sergio Massa, who are now likely to play an important role in the opposition.

Mr Scioli, who traded fierce barbs with Mr Macri during the campaign, described their discussion as “mature”. “It is time to act together,” he said.

Ms Segal hopes Argentines will give Mr Macri’s government the chance to bring strong growth and low inflation back to Argentina. If he succeeds in building confidence, Argentina could begin to attract “huge” investment.

“But restructuring an economy takes time, so people will have to be patient,” she said.