 Preparations for the offensive were already underway . The logistical build @-@ up began in mid @-@ year , and by January 1968 , 81 @,@ 000 tons of supplies and 200 @,@ 000 troops , including seven complete infantry regiments and 20 independent battalions made the trip south on the Ho Chi Minh Trail . This logistical effort also involved re @-@ arming the Viet Cong with new AK @-@ 47 assault rifles and B @-@ 40 rocket @-@ propelled grenade launchers , which granted them superior firepower over their less well @-@ armed ARVN opponents . To pave the way and to confuse the allies as to its intentions , Hanoi launched a diplomatic offensive . Foreign Minister Trinh announced on 30 December that Hanoi would rather than could open negotiations if the U.S. unconditionally ended Operation Rolling Thunder , the bombing campaign against North Vietnam . This announcement provoked a flurry of diplomatic activity ( which amounted to nothing ) during the last weeks of the year . 
