Foreign Minister Mevlut Cavusoglu said the presence of Turkish troops in the gas-rich Gulf country was not connected to the ongoing crisis between the Arab countries.

"We believe this demand is both unrealistic and irrelevant," the Turkish minister said, quoted by Qatar's pro-government Al-Watan and Qatar Tribune newspapers.

Turkey and Qatar had signed a defence agreement in 2014, "long before the Gulf crisis", he added.

Cavusoglu also said the diplomatic impasse should be resolved without delay.

Saudi Arabia, the United Arab Emirates, Bahrain and Egypt called for the closure of the Tariq bin Ziyad camp in Doha as part of a string of conditions to end their diplomatic and political isolation of Qatar.

The Saudi-led boycott imposed a blockade on Qatar in June 2017 over allegations the emirate supports radical Islamist groups and is seeking closer ties with regional arch-rival Iran.

Qatar denies the charges, accusing its neighbours of seeking regime change.

Closure of the Turkish base was one of 13 demands made by the Saudi-led countries, as well as a call for an end to all military cooperation between Doha and Ankara.

Qatar dismissed those demands as "neither reasonable nor actionable".

It is thought that 3,000 troops Turkish troops are on Qatari soil and that the base has a capacity for up to 5,000 military personnel.

In February, the Turkish ambassador Fikret Ozer said Turkish air and naval troops would eventually be stationed in Qatar.

Qatar and Turkey have reinforced their extremely close ties in recent years.

Emir Sheikh Tamim bin Hamad al-Thani was the first foreign leader to contact Turkish President Recep Tayyip Erdogan during the aborted Turkish coup in 2016.

At the beginning of the Gulf crisis, Turkey was at the forefront of nations to supply the Gulf state with food and services, following the blockade imposed by the Saudi-led nations.

Qatar also recently announced a $15 billion loan to Turkey's fragile banking sector and also gave a luxury jumbo jet -- reportedly worth around $400 million -- as a "gift" to Ankara.