LONDON (AP) — Britain has accelerated plans to increase the pension age, as rising life expectancy continues to put pressure on the public purse.

Work and Pensions Secretary David Gauke announced the change Wednesday, pointing out that paying for pensions for longer presents a challenge for the government.

Under the plans, the pension age rises from 67 to 68 from 2037 and 2039. Under current rules, the increase had originally been set to take place between 2044 and 2046.

Gauke says "there is a balance to be struck" between funding pensions while also ensuring fairness for future generations.

The agency says the number of people over state pension age is expected to grow by a third between 2017 and 2042, from 12.4 million in 2017 to 16.9 million in 2042.