Cambodian troops were seen riding through the capital Phnom Penh in armored military vehicles to reinforce defences at the border.
Cambodia and Laos reached an agreement for Lao soldiers to pull back from their shared border, easing the threat of a military confrontation.
Around 30 Laos soldiers have been stationed in Cambodia's northern Stung Treng province since April despite repeated requests by Phnom Penh for them to leave, according to strongman premier Hun Sen.
"I appeal to Laotian Prime Minister Thongloun Sisoulith to withdraw the forces out of Cambodia without any conditions, and the latest deadline is August 17", he said.
In addition to the jail term, Sok was ordered to pay about $2,000 in fines to the state and some $200,000 in personal compensation to Hun Sen.
Hun Sen said he had talked over the phone in recent months with the Laotian prime minister and recently sent him a letter but hadn't received an official reply.
"We are friends, but a friend can not step on (our) head", said the mercurial leader, who often leans on ultra-nationalist rhetoric to drum up support, especially ahead of election season.
Hun Sen said he had also ordered truck-mounted rocket launchers and ground troops to pull back in response to Laos' agreement to withdraw.
According to Hun Sen the Laos soldiers crossed into Cambodia to halt the construction of a road.
"Moments ago, I already ordered all troops that were mobilised yesterday to go back to their positions".
Hun Sen said a border commission from both countries would begin working in the area once troops have withdrawn.
An official at the Lao embassy in Phnom Penh told Reuters on Friday the border area was the subject of a territorial and demarcation dispute.