"I had no reason to believe that, you know, I was a citizen of any other country than Australia".
"Now I am going to make sure that I don't cry in my beer".
Prime Minister Malcolm Turnbull was due to travel to Israel on Saturday.
Fellow politicians Scott Ludlam, Larissa Waters, Malcolm Roberts and Fiona Nash's elections to parliament have also been deemed invalid.
Bloodhound preps for land speed record with 200MPH test run
The Bloodhound SSC auto is a feast of engineering knowhow, blending technology from F1 cars, fighter jets and even spaceships. Green set the record at 1227,98 km/h 20 years ago. "I'm designed for supersonic speed but this I can do easily".
Another government minister Matt Canavan, who the court heard might have inherited Italian citizenship from his Australian-born mother through his Italian grandparents, was allowed to stay in Parliament.
Joyce has been deputy prime minister since February 2016 when he was elected head of the National party, the junior partner in Australia's governing coalition.
Disqualified senators are replaced by members of their own parties without an election so the balance of power is not altered.
Joyce told lawmakers in August he had discovered he was a New Zealand citizen, throwing his position in parliament into jeopardy. He later found he was British because his father left Cyprus while it was a British colony.
Speaking Friday, Turnbull said it was "clearly not the outcome we were hoping for" but denied that his government faces any instability in the absence of Joyce.
Egypt: 55 policemen killed in gunbattle with militants
Egypt has been under a state of emergency since April when a twin church attack killed scores. The Muslim Brotherhood has denied any involvement in violent attacks against security forces.
Constitutional lawyer Anne Twomey said there may be a legal challenge to any decision Joyce took once questions had been raised about his eligibility.
The seven judges rejected the government's argument that five of the lawmakers, including three government lawmakers, should be exempt from the ban because they had not voluntarily acquired or retained citizenship of another country.
Australia's constitution states that members of parliament can not be "a subject or a citizen or entitled to the rights or privileges of a subject or citizen of a foreign power".
Joyce claimed he wasn't aware he held New Zealand citizenship and has since renounced it.
North Korea behind 'WannaCry' cyberattack on British hospitals - security minister
The National Audit Office said a cyber-attack which crippled a third of NHS hospitals in May could have easily been prevented. NHS organisations have not reported any cases of harm to patients or of their data being stolen as a result of WannaCry.