Qatar has called its tanks into action and warned neighbours that it will open fire on any ships that come into its waters.
The country’s military has been put on its highest alert level after an economic and diplomatic blockade was placed on it by other Gulf State nations over its alleged support for terrorists.
The Qatari government has written to leaders in Saudi Arabia, Bahrain and the UAE warning it will respond to any naval threat.
It has also bought 16 Leopard tanks out of storage in capital Doha, CNN reports.
The move comes after Saudi Arabia yesterday issued an ultimatum demanding that Qatar severs links with the Muslim Brotherhood and Hamas.
US President Donald Trump has offered to host a White House meeting if necessary, in a change of heart from his initial support for the Saudi-led boycott.
A string of countries this week cut ties with Qatar over what they say is the emirate’s financing of extremist groups and its ties to Iran, Saudi Arabia’s regional arch-rival.
Qatar strongly denies the allegations and has expressed a willingness to engage in talks to resolve the crisis.
The Arab countries closed air, sea and land links with Qatar, barred the emirate’s planes from their airspace and ordered Qatari citizens out within 14 days.
The White House has said that in a conversation with Qatari leader Sheik Tamim, Trump has ’emphasized the importance of all countries in the region working together to prevent the financing of terrorist organizations and stop the promotion of extremist ideology’.
Kuwait – which unlike most of its fellow Gulf Cooperation Council members has not cut off ties with Qatar – has been leading efforts to mediate.
Its emir Sheikh Sabah al-Ahmad Al-Sabah held talks on Wednesday with Qatari counterpart Sheikh Tamim bin Hamad Al-Thani, following talks with senior UAE officials and Saudi King Salman.
Trump, who had initially backed the measures against Qatar in a tweet, called Sheik Tamim on Wednesday with an offer “to help the parties resolve their differences”.
French President Emmanuel Macron has also reached out to Qatar, Saudi Arabia and Iran in a bid to kick off negotiations
Turkey, which works closely with Qatar in the energy sector, has walked a fine line between defending Qatar and abstaining from openly antagonising Saudi Arabia.
Ankara hosted Iranian Foreign Minister Javad Zarif this week for talks, including on Qatar.
In a sign of support for Doha, Turkey’s parliament on Wednesday approved an agreement to expand the number of troops deployed to a Turkish base in Qatar. The agreement did not detail a timeframe or the number of troops.
A top Gulf official, speaking on condition of anonymity, told AFP a major concern was the influence of Sheikh Tamim’s father, Sheikh Hamad, who had allowed the Taliban to open an office in Doha and helped arm Syrian rebels before abdicating in 2013.
‘The previous emir is a big supporter of this whole extremist agenda, so we do have an issue,’ the official said.