The travel alert comes a few days after the hostage attack in a Sydney’s café, which claimed lives of three people, including the attacker.

MOSCOW, December 20 (Sputnik) – The US government has discouraged American citizens from travelling abroad, after the Sydney café siege, which happened earlier this week, according to NBC News.

On Friday, the US government issued worldwide travel alert, warning US citizens of possible terrorist attacks and reminded them to be vigilant, according to the website of US Department of State.

“U.S. citizens should be extra cautious, maintain a very high level of vigilance, and take appropriate steps to enhance their personal security,” the statement says.

The travel alert states that the terrorist threat is unpredictable, while terrorist attacks can emerge in public places everywhere and anytime. The statement calls for people to be cautious in public places such as “hotels, shopping areas, places of worship, and schools”, referring to the recent siege of a Sydney café.

The attack on Sydney’s Lindt Chocolat Café took place on December, 15, when a gunman stormed inside and took 18 people hostage. The attacker, Man Haron Monis, was born in Iran, but had been granted Australian citizenship as asylum seeker. Monis reportedly was recently inspired by radical ideology and became follower of the Islamic State.

The hostage crisis claimed lives of three people, including the attacker. Four other café visitors and one police officer were injured, according to BBC.

The US travel alert is expected to remain in force until March 19, 2015.