TOKYO (AP) — The population of Japan's capital — one of the biggest cities in the world — has surpassed 13 million for the first time.

Tokyo counted 13.01 million residents as of April 1, up 0.5 percent from the same month a year earlier, the Tokyo Metropolitan Government said Wednesday.

The growth contrasts with the overall demographic trend in Japan, where people have long lifespans and stubbornly low birth rates. The result is a shrinking population and tax base that threaten to undermine the world's second-biggest economy.

Japan's total population peaked at 127.84 million in 2004, according to the Ministry of Internal Affairs and Communications.

Meanwhile, Tokyo is thriving, adding 1 million people over the last decade. A recent boom in condominium construction and an expanding foreign community contributed to the population growth, particularly in central Tokyo, said Yuko Sakurai, a spokeswoman for the Tokyo government's statistics division.

The number of foreigners living in Tokyo is up 46 percent since 2000 and stood at 418,116 as of Jan. 1, according to a separate Tokyo government population report.

The search for better jobs is also drawing people to Tokyo.

Though recovering, Japan's labor market remains weak. The country's unemployment rate hit a record high of 5.6 percent in July last year as the global downturn forced companies to cut costs. Workers outside Japan's urban hubs have been particularly hard hit.

Tokyo's population is expected to keep increasing until peaking around 2015, Sakurai said.

Still, authorities are preparing for the inevitable demographic shift later this decade and beyond. Tokyo Governor Shintaro Ishihara, who has vowed to build new homes for seniors to accommodate the growing elderly population, has also introduced measures to ease the burdens of child-rearing in an effort to boost the birthrate.

In a speech in February, he said Tokyo would commit 47.5 billion yen ($510 million) over three years to bolster day care, health care and other support services for families with children.

The Tokyo Metropolitan Government administers a sprawling region that covers 845 square miles (2000 square kilometers) and comprises 23 central wards, 26 cities, five towns and eight villages. About two-thirds of Tokyo's residents live in the wards.

Its population data is based on the 2005 national census and subsequent monthly counts of resident registries.