The opening of the new Humboldt Forum museum in Berlin has been delayed until 2020 due to construction delays.

Housed inside a reconstructed Prussian palace in the east of the city, the museum – which is named after the explorer and polymath Alexander von Humboldt – was due to open in September 2019.

However, in a status update, it was admitted "it would be unrealistic to expect the building to be fully operational by the end of 2019", and that the "stage-by-stage opening cannot begin until 2020".

The statement added that a new timetable would be presented on 26 June.

The main focus, currently, is on completing the building's technical services, which are mostly only partly operational, with some systems requiring adaptation after technical evaluation.

Construction is still underway on the rooftop restaurant, the ground floor and basement, and on the floor of the pedestrian passageway, while the facades of the Schlüterhof courtyard are still partly under scaffolding due to plastering work and final tasks.

The Humboldt Forum is intended to "bring together diverse cultures and perspectives and seek new insights into topical issues such as migration, religion and globalisation", according to its website. The cost of the project is reported to be €600m (US$671.6m, £536.18m).

A disagreement has also sprung up about whether the museum should charge for entry to its permanent exhibitions. Former British Museum director Neil MacGregor, who chairs the Humboldt advisory committee, has called for free admission, while Berlin's culture senator Klaus Lederer has ruled that the Humboldt should not be exempt from entrance fees, so as to not negatively affect smaller cultural events.