Alistair Burt has joined more than 120 parliamentarians in signing a letter to Theresa May amid concerns of hundreds of thousands of people suffering in Aleppo.
Syrian rebel forces have lost control of much of the city - as government troops try to re-take it.
In the letter, MPs state: "Air-dropping aid is only ever a last resort, but who can credibly claim we have not reached that point?"
They also claim nearly 100,000 children are facing the "slowest, cruellest death" without access to food and medical supplies.
Mr Burt, who represents North East Bedfordshire, explained his reasons for signing the letter on Premier's News Hour.
He said: "You're left with a situation now of absolute desperation in Aleppo and you only have to hear the stories coming out to know just how bad the circumstances are.
"And in those circumstances the only thing left open is dropping the aid from the sky."
The Foreign Office has refused to rule out the option of air-dropping aid.
In a statement, a spokesman said: "We will continue to look at all options with our international partners to alleviate the suffering of millions of Syrians."
Mr Burt says the reputation of world leaders is at stake.
"People will come to the conclusion that international institutions no longer work.
"Accordingly states can pick and choose those who they're prepared to listen to and might will always overcome right."
The MP is also urging fellow Christians to remember this situation in prayer.
He said: "Behind all this are people who want to get on with their lives and want everything that we take for granted - the ability to go to the shops, to educate their children, to be treated in hospital and not to be bombed every day.
"That must be worth praying for."
Listen to Alistair Burt speaking to Premier's Marcus Jones: