Former US defence secretary Robert Gates, who served under presidents George Bush and Barack Obama, focused on cuts to the UK Navy as particularly damaging. He said that for the first time since World War One, Britain did not have an operational aircraft carrier.
The Ministry of Defence has defended levels of spending within the military spending, and said that the UK had the best equipped and well trained armed forces outside of the US.
More top news
There is no evidence the Westminster attacker Khalid Masood was associated with so-called Islamic State or al Qaeda, the Met Police said.
Janet Ajao said in a statement: "I do not condone his actions nor support the beliefs he held that led to him committing this atrocity."
After the PM triggers Article 50, Britain will need the other EU nations to agree to deals. Gibraltar could be key to Spain's demands.