Turkey is one the few powerful countries to stand squarely by Qatar after Saudi Arabia, Egypt and other states severed ties with Doha.
Qatar held military exercises with Turkish troops on Monday, demonstrating one of its few strong alliances after two weeks of ostracism and economic isolation imposed by its neighbours.
Qatar's state-funded pan-Arab news channel Al Jazeera showed footage of a column of armoured personnel carriers moving through the streets.
It reported that additional Turkish troops had arrived in Qatar on Sunday for the exercises, although military sources in the region said the operation actually involved Turkish troops that were already present rather than new arrivals.
Turkey is one of the few powerful countries in the Middle East to stand squarely by Qatar after Saudi Arabia, Egypt and several other states proclaimed it a supporter of terrorism and cut off all economic and diplomatic ties.
Qatar, the world's richest country per capita, has used its wealth over the past decade to exert outsized influence in the Middle East, backing factions in civil wars and revolts across the region.
It denies supporting terrorism and says it is being punished for straying from its neighbours' political line of backing the region's authoritarian hereditary and military rulers.
"The blockade has been ongoing for two weeks and the blockading nations have offered no formula for resolving the crisis," Sheikh Saif Bin Ahmed al Thani, Director of Qatar's Government Communications Office, said in a statement on Monday.
"It is unfortunate that our neighbours have chosen to invest their time and resources in a baseless propaganda campaign," he said, calling the terrorism accusations a "publicity stunt."
Test for the United States
The diplomatic dispute is an important test for the United States, which is close allies of countries on both sides and has the headquarters of its air power in the Middle East in Qatar.
President Donald Trump has strongly supported the sanctions against Qatar, even though his State Department and Defense Department have tried to remain neutral. The Pentagon approved a $12 billion deal to sell warplanes to Qatar last week.
In a show of support for Qatar, Turkey's parliament fast-tracked legislation on June 7 to allow more troops to be deployed to a military base in Qatar that houses about 90 Turkish soldiers under an agreement signed in 2014.
Turkey has said it will deploy 3,000 ground troops at the base, primarily to serve as a venue for joint training exercises.
Turkey has maintained good relations with Qatar as well as several of its Gulf Arab neighbours.