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 VC with new AK-47 assault rifles and B-40 rocket-propelled grenade launchers, which granted them superior firepower over the ARVN. 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.