On Thursday, the US military dropped its so-called Mother Of All Bombs on a remote town in eastern Afghanistan, near the Pakistani border.
It targeted a network of tunnels and caves used by a local branch of the Islamic State of Iraq and the Levant (ISIL) group.
An Afghan governor said the 10,000kg bomb killed at least 100 fighters.
It is believed to be the most powerful non-nuclear bomb dropped by the US in any battlefield.
And on Saturday, a US government agency announced the successful test of a mock nuclear bomb in Nevada.
It is part of an effort to upgrade one of the nuclear weapons that has been in the US arsenal for decades.
Are America's military actions causing an increase in global defence spending?
Countries around the world are increasing their defence spending.
The Stockholm International Peace Research Institute says the US is still the biggest spender when it comes to its military.
It is followed by China, the UK and Russia.
Trillions of dollars are spent every year to get the latest and most advanced military hardware.
But critics say that is leading to an arms race that will have long-term consequences
Presenter: Laura Kyle
Oubai Shahbandar - military analyst who served as Middle East foreign affairs specialist under three US defence secretaries at the Pentagon
Sergey Strokan - political analyst and columnist at the Russian newspaper Kommersant
Tariq Rauf - nuclear arms control specialist
Source: Al Jazeera News