London  -  Britain's Queen Elizabeth II and Prince Philip were Tuesday leaving for a four-day state visit to Turkey, their first to the country since 1971.

The royal trip follows an invitation from President Abdullah Gul and comes more than 36 years after the British monarch and Prince Philip last visited the secular Islamic republic.

The Queen, 82, and the Duke, who is 86, will lay a wreath at the tomb of Kemal Ataturk, the founder of modern Turkey, in the capital Ankara, Tuesday.

The royal couple will also formally meet the president at his palace, where his wife, Hayrunnisa, is expected to wear a controversial Islamic headscarf, banned in public and government buildings.

The delicate issue of the headscarf could confront the Queen as soon as she stepped off the plane, diplomatic sources in London said.

In the evening, a state banquet will be held in the Queen's honour at the president's palace.

Later in the trip, the royal couple will visit the western city of Bursa and will tour a school in Istanbul which has links with British students, as well as visiting the city's Modern Art Museum.

The royal visit is seen as highlighting the importance of Britain's relationship with Turkey. Britain has always been a strong supporter of Turkey's efforts to join the European Union.

Turkey became an official candidate in 1999 and entered formal accession negotiations in 2005. The country is also seen as a key ally in the fight against terrorism.

The tour comes less than six months since the Pince of Wales and Duchess of Cornwall visited Turkey last November. (dpa)