Visa requirements for Ukrainian citizens
For traveling to certain countries, Ukrainians do not need to use a passport, as they may use their Ukrainian identity card or internal passport.
Documents which give the right to leave Ukraine and to enter Ukraine and certify the identity of a citizen of Ukraine while staying abroad are:It's important to know, that the special rules of arriving in a particular country should be studied carefully. Thus, in most countries that do not require visas or issue visas, upon arrival you must have a passport, which is valid for at least 3 months from of arrival to this country.
Visa requirements for Serbian citizens
As of May 2018, Bosnia and Herzegovina, Brunei, Grenada, Mauritius, Seychelles and Serbia are the only countries whose citizens may travel without a visa to China, Russia and the Schengen Area.
Before Serbia began issuing new biometric passports in 2008, its citizens travelled using old Federal Republic of Yugoslavia passports that at that time provided visa-free access (or visa on arrival) to only 19 countries.