Japan’s economy shrank in the final three months of 2015, the government said on Monday, undergoing a more severe contraction than experts had expected amid signs that global growth was stalling.

The Cabinet Office said output in Asia’s second-largest economy declined by 1.4 percent in annualized, price-adjusted terms. Most sectors — from consumption and housing investment to exports — deteriorated.

The decline in Japan’s gross domestic product was the second in three quarters, and was sharper than most private sector economists had forecast. Economists surveyed by Bloomberg had predicted a contraction of 0.8 percent, on average.

With concerns about the health of the global economy sending shudders though the financial markets, Prime Minister Shinzo Abe is facing what may be the toughest test yet of his three-year-old campaign to lift Japanese growth rates and end two decades of deflation.

One crucial pillar of that campaign — a weaker currency — has lately begun to crack. The yen dropped by about 40 percent against the dollar from the time Mr. Abe took office in late 2012 until the end of last year, as the Japanese central bank carried out an aggressive program of monetary stimulus.

The devaluation of the yen enriched automakers and other big companies that earn most of their revenues abroad, and sent the Japanese stock market soaring. It helped nudge consumer prices higher, too, another central goal of Mr. Abe’s economic agenda, known as Abenomics.

But since late last year, a flight to safe assets by global investors has reversed the yen’s direction. Stocks have tumbled — the Nikkei 225 average lost 12 percent last week, its worst weekly performance since the depths of the financial crisis in 2008. Inflation has slipped back to around zero.

In response, the central bank — the Bank of Japan — announced last month that it would take the unusual step of cutting its benchmark interest rate below zero, joining a group of European countries that are also struggling with deflation.

The Nikkei surged more than 5 percent in early trading on Monday despite the gloomy economic report, possibly reflecting a slight easing in the yen after Asian markets closed on Friday.

Mr. Abe’s governing coalition faces an election for the upper house of Parliament this summer. Analysts and advisers say he has been counting on public support for his economic policies to extend the coalition’s majority there. The strategy now looks less bankable, though it is unclear whether Japan’s weak collection of opposition parties can capitalize on any voter backlash.

For all of 2015, the Japanese economy eked out growth of 0.4 percent, the government data released on Monday showed.

Japanese G.D.P. data are often subject to sharp future revisions. The low growth rate, meanwhile, means those changes can easily make the difference between an economy that appears to be growing and one that is shrinking. Last quarter, for instance, the government initially said the economy was in recession, having contracted for two straight quarters, only to declare a few weeks later that output had actually grown.

Even so, the economic contraction measured by the government’s data on Monday took place as the recent financial market turmoil was only beginning. Should the volatility continue, analysts say, Japan could fall into recession for real this time.