Tourist Visa in Hanoi

Hi, you are suggested to apply for it in advance in South Korea if time permits (under rush service if necessary). To apply in a third country is difficult now as I know.

In fact, I am leaving for China tomorrow with my single entry one which I applied before. But after the trip in vietnam, I need another one to go back again.
Why is it difficult to apply in the third country?

Yes, you may have a try anyway if you are leaving soon. The application in a third country is possible but applicants should be working or studying with long-term residence permit in the said country. In most countries, the embassy/consulate does not accept applications from temporary visitors.