The UK government will do “whatever it takes” to keep the country safe from international threats, Prime Minister Rishi Sunak said on Monday, after <a href="https://www.thenationalnews.com/world/us-news/2023/02/09/china-spy-balloon-programme-pentagon/" target="_blank">four mystery objects were shot down </a>over North American airspace. <a href="https://www.thenationalnews.com/tags/us/" target="_blank">US fighter jets</a> shot down the most recent “unidentified object” on Sunday — the fourth suspicious aircraft to enter US or Canadian airspace in a week that began with the shooting down of a suspected Chinese <a href="https://www.thenationalnews.com/tags/spy-services/" target="_blank">spy balloon</a>. Mr Sunak said the UK was in “constant touch” with allies and that “national security matters” prevented him from elaborating. “I want people to know that we will do whatever it takes to keep the country safe,” Mr Sunak said. “We have something called the quick reaction alert force which involves Typhoon planes, which are kept on 24/7 readiness to police our airspace, which is incredibly important. “I can’t obviously comment in detail on national security matters, but we are in constant touch with our allies and, as I said, we will do whatever it takes to keep the country safe.” Mr Sunak did not comment the possibility of similar incidents happening in UK airspace. “People should be reassured that we have all the capabilities in place to keep the country safe,” he said. On February 4, the US military downed a suspected Chinese spy balloon off the Carolina coast after it travelled over sensitive military sites across North America. Last Friday, an unknown “car-sized” object flying in US airspace off the coast of Alaska was shot down. Two further objects were seen and destroyed — one on Saturday and another on Sunday. UK Defence Secretary Ben Wallace announced that a security review would be conducted after the North American incidents. British Transport Minister Richard Holden has suggested that it was “possible” that a Chinese spy balloon may already have been used over the UK. “It is also possible, and I would think likely, that there would be people from the Chinese government trying to act as a hostile state,” he said. Mr Holden said the UK had to be “robust” in how it dealt with Beijing, admitting that the UK government was “concerned about what’s going on” in the US. Downing Street said that the UK was “well prepared” to deal with security threats to British airspace, with threats judged on a “case-by-case” basis. The Prime Minister’s official spokesman did not use Mr Holden’s word “hostile” to describe China, but indicated that the foreign policy designation of the country will be reviewed as part of the country's defence review.