Presumably metric units, because that's what Burma's biggest trading partners use.Myanmar does not have an official measurement system. Government websites use either imperial or metric units, and sometimes both. In 2011 and 2013, the Ministry of Commerce announced that it was preparing to adopt the metric system, but this never happened.
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The deputy minister replied that the ministry is working to design a metrology bill, which will establish standard measurement units for the country.

I haven't been able to find anything with any detail on Liberia and the metric system.
Some officially-metric nations are only part of the way there, it must be conceded. Nations like Canada and the UK.
The US had a push to adopt the system in the late 1970's, but it fizzled out. Seems to me like a casualty of the end of the Sixties reform era, much like the Equal Rights Amendment and abortion.
More recently, Lincoln Chafee included a proposal to convert to it in his running for President in 2015 (Switching to the Metric System Is Officially a Presidential Campaign Issue Mother Jones, Chafee: Go bold, go metric - CNNPolitics). He is a former US Senator from Rhode Island.
So the US is likely to continue to muddle ahead, with the metric system mainly being used in technical and behind-the-scenes applications.