The US State Department has issued a travel warning for American travellers to Europe. It has urged them to be vigilant in public places or mass transportation and to take extra caution during any religious event.

A Europe-wide travel warning has been issued on transport networks and at tourist sites after the Belgium triple attacks.

“Terrorist groups continue to plan near-term attacks throughout Europe, targeting sporting events, tourist sites, restaurants and transportation,” read the statement.

The Obama administration has increased security at major airports and transit hubs across the country, reported abc7.

Obama declared in Havana, “we will do whatever is necessary to support our friend and ally Belgium in bringing to justice those who are responsible.”

After offering his condolences to Belgian Prime Minister Charles Michel, he said, “the world must unite. We can and we will defeat those who threaten safety and security of people all around the world.”

Andrew Cuomo, the governor of New York City said that the security has been tightened at the transport hubs, bridges and tunnels in his jurisdiction.

He stated, “Public safety is paramount, and I want the people of this state to know that we are working with all local and federal partners, remaining vigilant and taking all necessary measures to keep New Yorkers safe.”

According to Mail Online, officials are also planning extra security measures for inbound flights from Belgium. Reportedly, it is one of the 38 countries whose citizens do not require a visa to enter the states. Authorities are also considering some other security measures including an extra layer of security before entering airport checking lounge.

Despite the fact that passengers in the country expressed their horror for any wave of attacks in the future, New York Senator Charles Schumer stated that overseas Americans appeared more vulnerable to him.

He said, “There is no credible threat aimed at New York City or at the United States. The focus of ISIS up to now has been in Europe.”

Homeland Security Secretary Jeh Johnson echoed Schumer’s view and emphasized that there is no “specific, credible, intelligence” indicating a similar attack on America.

Experts believe that the Belgium attacks are the latest in the series of attacks planned by ISIS and Western intelligence is determined to detect and interrupt any future attack.