McDonald's has today missed Wall Street estimates for quarterly profit as most of its restaurants closed or limited their services to delivery, drive-through and take-away to curb the spread of Covid-19.

The world's largest fast-food company said about 75% of its about 39,000 restaurants around the world were operational as of today, including almost all of its nearly 14,000 restaurants in the US.

They remain closed in Ireland but earlier this week McDonald's said it was carrying out operational tests this week to explore what reopening its restaurants in the UK and Ireland might involve.

The company said it had resumed operations in a majority of its restaurants in China, where the virus was first detected late last year, although demand remained low as consumers had not fully returned to their routines. 

"The global crisis caused by the Covid-19 pandemic has significantly disrupted our business, and we continue to operate in a very challenging and unpredictable environment," chief executive Chris Kempczinski said.

The burger chain had pre-announced a 3.4% fall in first-quarter comparable store sales earlier this month, with US sales rising just 0.1% powered by strong demand before the pandemic.

In March alone, global comparable sales fell 22.2%, the company had said in early April. 

The health crisis has forced government-led lockdowns, bringing dine-in businesses for several restaurants to a halt towards the end of the first quarter.

Earlier this month, McDonald's withdrew its outlook for the year, joining other restaurant chains, citing uncertainties related to the health crisis and its impact on the global economic conditions.

It said today its net income fell to $1.11 billion, or $1.47 per share, in the first quarter ended March 31 from $1.33 billion, or $1.72 per share, a year earlier. 

Analysts were expecting a profit of $1.57 per share, according to IBES data from Refinitiv. 

Revenue fell 6.2% to $4.71 billion, but was above Wall Street estimates of $4.65 billion.