Nigerian President Muhammadu Buhari will sign the government's long-delayed budget into law on Tuesday, Information Minister Lai Mohammed said on Friday.

In May, Nigeria's parliament passed a record 9.12-trillion naira ($28.95-billion) budget for 2018 aimed at boosting growth eight months before the country's next presidential election. But it still needs to be returned to Buhari to be signed into law.

"We will sign it off on Tuesday," Mohammed told Reuters on the sidelines of a visit to London.

The total sum laid out in the spending plan passed by the Senate is higher than the 8.6-trillion-naira budget presented to parliament by President Muhammadu Buhari in November.

Mohammed said he expected the delay would have little effect on government projects.

"Even once a budget is passed, there are still processes, due diligence to be done ... this takes time."