Nato states will increase their defence spending by $100 billion in response to Donald Trump's demands that European allies shoulder a greater financial burden, the alliance's secretary general has said.

Jens Stoltenberg said on Sunday that the alliance had heard Mr Trump's call for non-US members to shoulder a greater financial burden "loud and clear" and that allies are "stepping up."

In conciliatory comments apparently designed to smooth over repeated public criticism of other alliance members by the US leader, Mr Stoltenberg said member states had agreed to add $100 billion to defence budgets over the next two years.

Mr Trump has repeatedly complained that other members of Nato do not meet their spending commitments, including a blistering tirade at the NATO summit in Brussels in July in which called other member governments "delinquent."