Uncertainty reigns as Singapore travellers and travel agents turn an apprehensive eye towards the United States, after the inauguration of businessman Donald Trump as President.

Compared with the first three quarters of last year, travel search engine Kayak says the average daily number of searches from Singapore for destinations in the US had dropped by 31 per cent after Mr Trump's election on Nov 9, a decline that lasted until the middle of last month.

Though searches bounced back after his inauguration on Jan 20, they dropped again after the announcement of his travel ban - this time by 10 per cent compared with the same period last year.

The ban, an executive order signed by Mr Trump on Jan 27, blocked the arrival of travellers from the predominantly Muslim nations of Iran, Iraq, Yemen, Syria, Libya, Somalia and Sudan for 90 days, and suspended US refugee resettlement for 120 days.

In the week that followed, the ban caused mass confusion and extensive delays at airports, where US residents, green-card holders and visa holders alike were detained or turned away by immigration officers.

These actions prompted mass demonstrations at international airports around the country, where thousands arrived to express their outrage at the alleged anti-Muslim bias and unconstitutional nature of the ban.

The protests were held just a week after millions of men and women marched in cities and towns across the country to demonstrate against the conservative and right-wing policies of the new President, a day after his inauguration.

Though the travel ban was suspended by a US federal judge on Feb 3, and the suspension unanimously upheld by a US Court of Appeals last Thursday, Mr Trump's response to the court's decision - an all-caps tweet which read: "See you in court, the security of our nation is at stake!" - suggests the issue will not be disappearing any time soon.

Already, the effects of the ban have impacted international travel to the US. On Feb 1, Bloomberg News reported that within two days, the ban had shaved US$4.9 billion (S$7 billion) off the market value of the country's biggest airlines.

Last Thursday, global news agency Agence France-Presse reported that international travel bookings to the US had fallen by 6.5 per cent after the travel ban, compared with the same period last year, and that the ban had deterred travellers from beyond the affected countries from making a trip to the US.

Ms Alicia Seah, director of communications at travel agency Dynasty Travel, says the political uncertainties in the US and an escalating US dollar exchange rate - now at US$1 to S$1.40, compared with US$1 to S$1.38 before the election - are likely to affect bookings.

The agency anticipates a drop of 15 to 20 per cent in demand for trips to the US in the first half of this year.

Ms Seah says: "Leisure travellers want to travel with peace of mind and people planning their travel from next month onwards will put their US travel plans on hold at this juncture."

She adds that travellers will likely turn their attention to destinations, such as Australia, New Zealand or places in Asia.

Other agencies, such as Chan Brothers Travel and Flight Centre, say that so far, interest in US destinations is holding steady as travellers wait to see what will come of Mr Trump's policies and the unrest they have caused in the US.

Ms Suyin Lee, managing director for Flight Centre Travel Group Singapore, says: "While there is a lot of speculation, it is too early for us to form an opinion on the impact of the ban."

But Mr Fazal Bahardeen, founder and chief executive of CrescentRating, a rating and accreditation service for Muslim-friendly travel, says the ban will dissuade many Muslims from going to the US for leisure and will impact business trips too.

"No one wants to go to a place where he might be subjected to 'extreme vetting' just because he is Muslim," he says. "It's not really about physical safety, it is more about being unwelcome."

He advises Muslims travelling to the US to buy maximum travel insurance coverage and have all travel documents - from hotel reservations to flight tickets to invitations if travelling for business - printed and in order before the trip. Any hosts in the US should be informed of the travel plans and, if possible, wait for the travellers at the airport.

The ban is prompting local Muslim-oriented agencies to reconsider plans to initiate itineraries to the US.

Mr Aurang Zeb, manager, of Muhibbah Travel in Beach Road, says it had plans to launch packages to the US later this year, but will now wait and see how the ban and its ramifications develop.

It is too stressful a proposition for Mr Ayoob Angullia, managing director of Shahidah Travel in Victoria Street. He plans to remove a tab on his website indicating that tours to the US are "coming soon" and will not be considering any trips to the country in the near future.

In his 30 years in the industry, he says, he has never seen a ban like this.

"When you are going somewhere for a holiday, you are going so that you can relax. I don't want to be harassed or detained at the airport... I want to have peace of mind when I move around," he says.

Being detained at the airport is a primary concern for public servant Iskandar Reindio, 36. He wanted to cancel his trip to New York and Los Angeles, scheduled for next month, but was unable to get a refund for the United Airlines ticket he bought in November.

"I'm Muslim and I have Arabic features... The chances of me being held at the airport or deported back to Singapore seem high and make me worried."

He has purchased extra travel insurance as a safeguard against any changes in travel plans and feels a little better now that the ban has been suspended, but otherwise says he can only hope for the best.

Though not a Muslim, Kiss92 radio DJ Joshua Simon, 26, was also worried that as a Singaporean of Indian descent, his brown skin might make him a target at immigration or of racial attacks.

Friends had advised him to cancel or reschedule his two-week trip to New York, but he left for the US on Feb 2 anyway and is now enjoying the snowfall and time with his friends in Brooklyn.

"I was worried about being treated with hostility, but now that I'm here, I see how diverse New York is, with so many nationalities, even more than in Singapore," he says.

The trip is the fulfilment of a life- long dream to visit New York and he is happy he took the chance.

"I didn't want fear to dictate my life," he says.