AstraZeneca has asked Thailand to extend the timeline for the delivery of 61 million doses of its Covid-19 vaccine by five months, a deputy minister said, a move likely to further disrupt the country's sluggish vaccine rollout.

The reported request points to a slow production ramp-up at its local manufacturing partner, which had initial production and delivery issues, even as AstraZeneca reassured it would be back on track from this month to meet its supply commitments to Thailand and other Southeast Asian nations, Reuters reports.

The comments come a day after Thailand said it was considering curbing exports of the locally produced AstraZeneca vaccines to fight its own crisis, sparking concerns of vaccine protectionism.

The Thailand dispute marks a fresh setback for the drugmaker which had other production glitches earlier and is in a legal battle with the European Union over shipment delays, while its vaccine has been linked to rare cases of blood clotting.