President Recep Tayyip Erdogan reaffirmed Turkey's support for Qatar on Friday and called for the blockade against Doha by several Arab states to be completely lifted.
Erdogan said the recent crisis in the Gulf region serves only those who were gaining from instability in the Middle East.
"Unfortunately, the recent tension between the Gulf countries have overshadowed the joy of the holy Ramadan of all Muslims. It is wrong to add more crises as the Islamic world struggles with many other difficulties," Erdogan said at an event in Istanbul.
"It is just not right to waste our energy with our domestic affairs while dirty plans have been made concerning the future of our region. I call upon my brothers in Gulf, dear leaders and people; there is no winner in the fight between brothers."
Erdogan also called on Saudi Arabia to show leadership in the region.
"I have a request to the Saudi administration: you are the biggest in the Gulf, the strongest...you should be the leader of fraternity there, you should bring everyone together," he said.
Commenting on the criticism against Turkey for providing food supplies and military support to Qatar, Erdogan said: "Our friends in the Gulf were not bothered by the US base in Qatar but why are they concerned about a Turkish base."
The Turkish president said he has never known Qatar to give support to terror organisations.
"There are those who are uncomfortable with us standing by our Qatari brothers, providing them with food. I'm sorry, we will continue to give Qatar every kind of support. Until now I have not seen Qatar give support to terror."
Turkey's parliament pushed troop deployment to Qatar through a bill on Wednesday and Erdogan's rapid approval of it, announced by his office late on Thursday, was followed by its publication in the Official Gazette on Friday.
Media reports say the deployment will initially include warplanes, ships and some 200-250 troops.
Led by Saudi Arabia, several states in the Middle East and Africa have severed diplomatic ties with Qatar since Monday, accusing it of supporting "terrorism" and for its ties with Iran - a charge Qatar has dismissed.
Trump says Qatar must halt "funding terrorism"
On Friday, US President Donald Trump also turned up the heat on Qatar, warning it to stop "funding terrorism" while his state department urged Arab states to ease their blockade on the country.
"The nation of Qatar unfortunately has historically been a funder of terrorism at a very high level," Trump told reporters at the White House.
"We had a decision to make, do we take the easy road or do we finally take a hard but necessary action. We have to stop the funding of terrorism. I decided ... the time had come to call on Qatar to end its funding," he said.
Tillerson calls for easing blockade
In a different position to Trump's hard line, US Secretary of State Rex Tillerson called on all parties to end the crisis.
"We call on the kingdom of Saudi Arabia, the United Arab Emirates, Bahrain and Egypt to ease the blockade against Qatar," he said.
Tillerson told reporters at the State Department that the crisis, which has cut transportation links and trade, had begun to hurt ordinary people in Qatar, impaired business dealings and harmed the US battle against Daesh.
Qatar is home to a vital US military base. Shortly after Tillerson's remarks, the Pentagon said that the Qatar blockade was "hindering" the ability to plan for long-term operations.
Qatar, which has developed an assertive foreign policy over the past decade, denies that it supports militants and says it is helping to reduce the threat of terrorism by backing groups that fight poverty and seek political reform.
It has vowed to ride out the isolation imposed on it by fellow Arab states and said it would not compromise its sovereignty over foreign policy to resolve the region's biggest diplomatic crisis in years.