Nigeria's President Muhammadu Buhari has finally signed into law a budget for 2016 after months of wrangling.

He had refused to approve the 6.08tn-naira ($30.6bn; £21bn) budget amid claims of mismanagement and kickbacks among the officials who drew it up.

The budget triples capital expenditure in Nigeria.

Some 34 projects will get extra spending to help revive the economy, including improvements to power, health, and transport.

"It is a great pleasure to sign the budget. It is a serious article of faith for the Nigerian people," the president said at a ceremony.

"The signing of the budget today will trigger concerted efforts to reflate the Nigerian economy, a key element of which is an immediate injection of 350bn naira into the economy by way of capital projects."

The budget is based on an oil price of $38 per barrel, slightly below the current global market rate of just over $40.

Mr Buhari delayed signing the budget after finding errors in the spending programmes. The former military head of state, who has embarked on a widespread anti-corruption campaign since taking office last May, has claimed some lawmakers removed and replaced spending proposals.

Delays in approving the expansionary budget have added to Nigeria's economic problems of slow growth and high inflation.

In his address, Mr Buhari said Nigeria was "experiencing probably the toughest economic times in the history of our nation".

The government is hoping to diversify the economy, produce more food, revive manufacturing and generate employment to help boost growth.

Infrastructure development is also needed, particularly in roads, housing and power supply for Nigeria's 180 million people.