Germany's finance minister says he's confident he can keep promises to balance the budget next year and is rejecting anew suggestions that the country should borrow to finance greater public investment.

Chancellor Angela Merkel is determined to stick to plans to get by without new borrowing next year for the first time since 1969, though Germany's growth outlook has weakened and Berlin faces calls from abroad to pump money into the economy.

Finance Minister Wolfgang Schaeuble acknowledged in Sunday's Welt am Sonntag newspaper that Germany "must invest more and improve our competitiveness." But he added: "We just don't want growth on credit."

Schaeuble said it's important to keep to promises and says he's confident a balanced budget can be achieved because "tax income doesn't react so quickly to economic changes."