vietnam has asked local authorities to tighten controls on imported milk and suspend the sale of products of unknown origin amid china 's tainted milk scandal , an official and press reports said tuesday .

What is a very short summary of the above text?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
vietnam tightens checks on milk imports amid china scandal