As a non-resident alien, at 59 1/2 can I access my 401 k account from outside the U.S to get distributions?

Absolutely.

If your former employer is willing to maintain your 401K account, there is no reason, in this age of email, webcoms and long-distance phone calls, why you cannot continue to maintain from your home country.

If your former employer is unwilling to maintain the account, roll it over to a rollover IRA in a brokerage house like Charles Schwab or Fidelity and they will be more than happy to maintain the account, regardless of where you live.