Pakistani and Indian authorities are working together to combat the worst invasion of desert locusts in decades in the region, which is threatening crops in both countries, Pakistan's foreign office has said.

The two countries - also bitter regional rivals - have been coordinating through the United Nations Food and Agriculture Organisation (FAO), on controlling the locust activity, sharing data and attending weekly meetings.

During a weekly briefing on Thursday, a spokesman from Pakistan's foreign office said a decision to work together was made at a ministerial-level meeting of Pakistan, India, Afghanistan and Iran in March.

The participants decided to revive communication between the regional countries through the FAO's Commission for Controlling the Desert Locust in South-West Asia (SWAC).

Pakistan is facing its worst locust infestation in two decades, prompting authorities to declare a national emergency.

Millions of locusts have also engulfed India's seven heartland states, including the western desert of Rajasthan, and threaten vegetable and pulse crops such as lentils and beans.

The last major locust surge was in 1993, when heavy rains created favourable breeding conditions for the insects along the India-Pakistan border.

Locust swarms can fly up to 150km (90 miles) a day, and the adult insects can consume roughly their own weight in fresh food each day. A small swarm can eat enough food to feed 35,000 people in one day, according to the FAO.