US President Donald Trump reaching to shake Turkey's President Recep Tayyip Erdogan's hand before a meeting at the Palace Hotel during the 72nd United Nations General Assembly in New York City. Photo: AFP

Turkey's Foreign Ministry on Friday issued a travel advisory for citizens travelling to the US, urging them to consider increasing terror acts and arbitrary arrests of Turkish citizens.

"The US has seen an apparent increase in terror attacks and violent incidents recently," the warning published on the ministry's website said.

The warning also pointed out the risk of "arbitrary arrests" of Turkish citizens, saying judicial decisions could be made by pre-established, unfounded claims and slander of the networks of US-based Fethullah Gulen, whom Ankara accuses of masterminding the 2016 coup attempt.

Turkey's travel warning came after the US State Department issued a similar warning to its citizens on Thursday, urging them to reconsider travel to Turkey "due to terrorism and arbitrary detentions" under an ongoing state of emergency.

Ties between the two NATO allies have been strained since the failed coup attempt in July 2016, amid the US's refusal to extradite Fethullah Gulen.

As for Syria issue, Turkey has strongly opposed US military support for the Syrian Kurdish People's Protection Units (YPG) militia, which Ankara views as an extension of the outlawed Kurdistan Workers' Party (PKK).

In late December, the US and Turkey lifted all visa restrictions against each other, ending a months-long visa dispute that began when two local employees of the US consulate were detained on suspicion of links to the coup.