Turkish President Recep Tayyip Erdogan challenged the United States to impose sanctions against his country over its stance on the conflict in Nagorno-Karabakh and its purchase of Russian weapons. “Whatever your sanctions are, don’t be late,” Mr Erdogan said, referring to US warnings for Turkey not to get directly involved in the conflict over the breakaway region of Nagorno-Karabakh, where Ankara supports Azerbaijan against ethnic Armenian forces. The Turkish leader also mentioned Washington’s threat of sanctions after Turkey tested the Russia-made S-400 air defence system. The purchase has already led to Turkey being shut out of the F-35 stealth fighter programme. “We stepped in for the F-35, you threatened us,” Mr Erdogan told a ruling party congress in the eastern city of Malatya on Sunday. “You said, ‘Send the S-400s back to Russia.’ We are not a tribal state. We are Turkey.” The dispute over the S-400s, which Nato says poses a threat to the military alliance and particularly endanger the technical secrets of the F-35, is among a number of recent disputes between Turkey and some of its Nato allies. These include gas exploration in the eastern Mediterranean that has threatened a confrontation with Greece, as well as Turkey's stance in Syria, where it has targeted America’s Kurdish allies. For months, the US warned Ankara that it risked sanctions under the Countering America’s Adversaries Through Sanctions Act if the S-400 system were activated. President Donald Trump, however, has held back on implementing the sanctions amid hopes Mr Erdogan would not go ahead with activating the missiles.