The United States has approved the sale of up to US$895 million (AU$1.3 billion) worth of the guided weapons. 

Australia is set to acquire 220 Tomahawk missiles, an offensive precision missile that typically launches from ships or submarines, as part of the yet-to-be-approved deal. 

The Tomahawk belongs to the cruise missile category, flying at subsonic speeds and low altitudes. The missile has gone through several variants over the years, with upgrades or improvements added to each design. 

The fourth iteration, called Block IV, has a range of 1,600 kilometres and can reach speeds of Mach 0.74.

The missile's guidance system allows it to switch targets during flight and can cruise for hours over a war zone while changing course instantly on command. 

The Tomahawk missiles are manufactured by Raytheon Technologies, a major defence contractor in the United States. 

The US has been the biggest user of Tomahawk missiles since their inception in the 1970s and has fired them over 2,300 times in combat, including in Afghanistan, former Yugoslavia, Somalia, Yemen, and Libya.

Block V, the latest variant of the Tomahawk, was introduced in 2021 and has more advanced features such as the ability to hit moving targets at sea and more diverse land targets. However, it is unclear which variant the Royal Australian Navy will receive.

In comparison, China possesses a variety of missiles, including intercontinental ballistic missiles (ICBMs) such as the DF-31, DF-41, and DF-5 that can hit targets from 7,000 to 15,000 kilometres away and can carry nuclear warheads. 

While Australia does not have ICBM capability, China's medium-range ballistic missiles known as MRBMs, such as the DF-21, have a superior range to the Tomahawk, reaching targets up to 2,150 kilometres away, and can carry nuclear warheads. 

Additionally, China's military has the HN-1, HN-2, and HN-3 cruise missiles that can hit targets from 600 to 3,000 kilometres away, carrying nuclear warheads and can be fired from various locations. 

China also has its anti-ship YJ-18 missile and its variants that can be fired from ships, submarines, and the ground, with a cruising speed of Mach 0.8 and can hit targets up to 540 kilometres away.