A diplomatic row between the US and Turkey deepened on Monday as Turkish authorities issued an arrest warrant for a second US consulate worker.

The warrant was issued scarcely 24 hours after the US announced it would suspend all non-immigrant visa services at all US diplomatic outposts in Turkey.

Ankara responded with a similar statement suspending non-immigrant visas at its Washington embassy.

The spat has strained relations between the Nato allies and threatened to disrupt travel for thousands of Turkish and American citizens.

It has also spooked investors. The Turkish lira dropped 2.4 per cent and shares in Turkey’s national airline and the country’s BIST stock index plummeted.

The US decision to suspend visas came less than a week after a US consulate worker in Istanbul was detained by the Turkish security services on suspicion of links to Fethullah Gulen, the US-based cleric Ankara blames for last year’s attempted coup.

John Bass, US ambassador to Ankara, said American officials had been given no reason for the arrest or told of any evidence against the staff member.

“This arrest has raised questions about whether the goal of some officials is to disrupt the long-standing co-operation between Turkey and the United States,” he said. “If true, this would put the people who work with, and work at, and visit our diplomatic facilities at risk.”