The keywords meta tag is not used at all for anything by Google and other serious search engines. Oh It could (and should IMO) be used as a spam signal however if it's abused.
Otherwise it's a simple thing: if the page text content is clearly relevant to a particular location, that's all you need. Well you also need for the content in general to be original, unique and compelling as per Google's guidelines.
Avoid at all costs creating location pages unless their content is specific to THAT location, with an office and phone number in that location. Otherwise it's all SPAM.
If you want to get results in search engine from a specific country or city, then you should work with local SEO practices. Here are the most important techniques of SEO to target a specific area or location:
Submit your website in local business directories
Use location in website content / Make footer and mention your full address with target city or country
Submit the site on Google maps and places to target your specific area
Make your website backlinks on those sites which contain good Alexa rank and the majority of traffic comes from the particular location where you need to get results
Google is getting more advanced where it not only ranks sites that are getting high CTR, less bounce rate and if user returning again to search engine for answer or not. Now they divide the users based on location and rank the sites which performed good in those locations. In simple, if you want to rank your page in all locations you should provide answer that satisfies most users in the locations you want to rank. Silo structure could also help you to rank in different locations for if you create separate page for each location.