The three-stage solid-fuel DF-41 is larger than the DF-31 missile, and has a range of up to 13,000-15000 kilometers. The DF-41 has ten warhead MIRV capability. It is an 80 ton missile.
The 8,000 km range DF-31 was successfully flight- tested in 1999 and 2000, and tests of the other longer-range mobile ICBM were anticipated within next several years. The DF-31 is about 42 tons.
Operational deployment of the DF-31 missiles began in 2006.
The upgraded DF-31A missile has a reported range of 11,200 km which allows targeting of most of the continental United States. It was designed with MIRV capability to hold 3 to 5 warheads, each capable of a 20–150 kt yield, but is thought to be armed with only one warhead with penetration and decoy aids to complicate missile defense efforts.
In 2017, China deployed another improved variant of the DF-31 called the DF-31AG or DF-31B with an off-road TEL, an increased range of 13000 km and MIRVs.
The US had fairly advanced ICBMs with the Minuteman III in the 1970s. Similarly USSR (Russia) had mature ICBM technology in the 1970s.