Qatar said Thursday it will not "surrender" and rejected any interference in its foreign policy, defying its Gulf neighbours in an escalating dispute over its alleged support for extremists.
In an interview with AFP, Sheikh Mohammed bin Abdulrahman Al-Thani said calls for a change in Qatari policy from Saudi Arabia and its allies, which cut diplomatic ties with Doha this week, were unacceptable.
"No one has the right to intervene in our foreign policy," Sheikh Mohammed said.
He also rejected "a military solution as an option" to resolving the crisis, and said Qatar could survive "forever" despite the measures taken against it.
"We are not ready to surrender, and will never be ready to surrender the independence of our foreign policy," he told reporters later, adding: "No one will break us."
Saudi Arabia, the United Arab Emirates, Egypt and Bahrain led a string of countries that 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.
On Thursday the four countries issued a list of individuals and entities they said had "terrorist" links to Qatar, in their first joint statement since severing ties with Doha.
The group said the list shows Qatar "announces fighting terrorism on one hand and finances and supports and hosts different terrorist organisations on the other hand."
But the document contains at least two names already designated internationally as terrorist financiers, and against whom Qatar took action, according to a previous US Department of State report.
Qatar strongly denied the earlier allegations and expressed a willingness to engage in talks to resolve the crisis.
The gas-rich emirate's satellite news giant Al-Jazeera has also emerged as a point of contention, and on Thursday the broadcaster said it was battling a major cyber attack.
Al-Jazeera tweeted that it was "under cyber attack on all systems, websites & social media platforms", and a source said it was trying to repel the hack.
The UAE and Saudi Arabia have banned Al-Jazeera from the airwaves and closed the channel's offices.
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 feud has raised fears of wider instability in an already volatile region that is a crucial global energy supplier and home to several Western military bases.
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.
US President Donald 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".
Qatar hosts the Al-Udeid military base, the largest US airbase in the Middle East. Home to some 10,000 troops, it is central to the US-led fight against the Islamic State group in Iraq and Syria.
Analysts say the current crisis is in part an extension of a 2014 dispute, when Saudi Arabia, the UAE and Bahrain temporarily recalled their ambassadors from Doha over Qatari support for Egypt's Muslim Brotherhood.
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.
Doha has for years forged its own alliances in the region, often diverging from the politics of the six-state GCC and taking in leaders of the Muslim Brotherhood, the Palestinian Hamas and members of the Afghan Taliban.
A senior Emirati official told AFP this week's decision was not aimed at a change of regime in Qatar but to pressure the country to reshape its policy.
"This is a foreign policy that has gone wild," state minister for foreign affairs Anwar Gargash told AFP. "We need to put everything in check."
Gargash said the four Arab states seek a "political commitment to change course" by Qatar, including ending its support for the Brotherhood and Hamas.
Bahrain on Thursday followed the UAE in announcing that expressing sympathy for Qatar over the sanctions was an offence punishable by jail.