The message, sent late yesterday and today to subscribers via major cell phone operators -- all state-owned -- didn't directly condemn the riots that have broken out this week following China's decision to deploy the rig off the coast of central Vietnam on May 1.
Vietnamese patrol ships sent to try and disrupt the rig are currently locked into a tense standoff with Chinese ships guarding it.
One Chinese worker was killed and scores more injured at a huge Taiwanese steel mill that was overrun by a 1,000 strong crowd.
"The prime minister requests and calls on every Vietnamese to boost their patriotism to defend the fatherland's sacred sovereignty with actions in line with the law," the text message said.
"Bad elements should not be allowed to instigate extremist actions that harm the interests and image of the country."
Vietnam's authoritarian leaders typically clamp down on public protests of any sort, but have allowed them this time.
The government appears to be trying harness the nationalist sentiment of its people to send a message of protest to Beijing and garner international sympathy. But it has to be careful that the forces it unleashes don't end up triggering chaos in a country with a long history of popular anti-China sentiment.
Neither China nor Vietnam has shown any sign of compromise. China and Vietnam have tussled for years over the competing claims, as have the Philippines and China.
