On social spending, Lindner said the unemployed needed to be brought into the labour market faster.
On international spending, Germany could "reduce the distance" between itself and the next biggest spender on development cooperation and international climate financing, Lindner said.
The minister said he did not want to specify yet which subsidies should be cut, but that there were numerous examples "where we should ask if they actually meet their targets or are out of date".
Lindner and his coalition partners are in intensive talks on how to fill the gap blown in the 2024 budget by the Constitutional Court last month.
The court found the coalition government's decision to re-allocate 60 billion euros of unused debt from the pandemic era to its climate and transformation fund to be unconstitutional.
The ruling also affects other off-budget funds that Germany has used over the years to finance government policy in order to comply with its self-imposed debt brake, which restricts the public deficit to 0.35% of GDP.
($1 = 0.9190 euros)
(Reporting by Victoria Waldersee; Editing by Kevin Liffey)