Prime Minister John Key has just returned from a top secret trip to Iraq to visit New Zealand troops.

The visit was held under tight security amid fears Islamic State militants might target the Taji airbase for an attack.

Key arrived on a Hercules from Dubai and was protected by elite SAS troops, due to the risk of Islamic State fighters posing as Iraqi soldiers.

Despite the heavy security, pictures of the visit were posted on Iraqi Prime Minister Haider al-Abadi's Facebook page on Monday.

The Prime Minister watched New Zealand forces training soldiers from Iraq's 76th brigade and visited the medical centre.

So far the trans-Tasman mission has trained 1600 soldiers, many of whom have been deployed to al Anbar province, the front line of the fight against IS.

It's the first time Key has visited troops in Iraq. Defence Minister Gerry Brownlee travelled there in June.

source: data archive