Key differences remain between London and Washington over the Iran nuclear deal and Chinese telecoms giant Huawei.
They were on display as British foreign minister Jeremy Hunt spoke alongside his US counterpart, Mike Pompeo on Wednesday.
The US Secretary of State was in the UK capital ahead of a controversial state visit by President Donald Trump next month.
Iran nuclear deal
Iran announced today that they plan to cease "some commitments" to a nuclear deal signed with the US, UK, France, China, Russia and Germany in 2015.
Under the agreement, Tehran agreed to limit its nuclear activities and allow in international inspectors in exchange for the lifting of crippling economic sanctions.
But last year President Trump announced the US was pulling out of the agreement, leaving the other countries battling to save it.
Speaking on Wednesday, Hunt said the nuclear deal was an important achievement of Western diplomacy.
"For as long as Iran keeps its commitments, then so too will the United Kingdom," he added.
Pompeo said that "obviously" the US has "made a decision different than the United Kingdom has" but that the US would work with European partners to make sure Iran does not have a pathway towards a nuclear programme.
Hunt called Wednesday's announcement a big moment for Iran, stating that their economy was in a state of distress and that pursuing nuclear capabilities would only make them less secure.
"If they break that deal, then there will be consequences," Hunt said. "It is certainly not in their interest."
Huawei and 5G
The United States has told allies like the UK not to use Huawei's equipment because of fears that it could be a vehicle for Chinese spying,
Huawei has categorically denied the accusations.
There is uncertainty over the UK's position on the Chinese telecoms giant and it caused the sacking of Britain's defence minister last week.
Gavin Williamson was fired after a probe into who leaked information from a UK National Security Council meeting.
Williamson denies being the source.
The leak led to media reports claiming Huawei could be awarded contracts for non-core elements of the UK's 5G network.
Pompeo said every country has a "sovereign right to deal with the challenge" but that the US needed to make sure that "places where American information is" and places where the US has its "national security at risk" operate "inside trusted networks".
Hunt said the UK had not made a final decision, but that they "would never take a decision that compromised our ability to share intelligence" with allies.
Watch Pompeo's and Hunt's press conference in full
Earlier on in the news conference, Pompeo said the "special relationship" between the two countries was "thriving despite what you may read in the papers."
Hunt said that the United Kingdom was looking forward to welcoming US President Donald Trump next month for the commemoration of D-Day and said the two countries stand together as allies.
On the issue of Brexit, Pompeo said the Trump administration was eager for Brexit to be resolved soon so the US could strike up a bilateral trade agreement with the UK, calling the UK one of the US’s most reliable partners.
Several times, the leaders insisted the countries were close allies in agreement with each other on key issues.
"I have great confidence that the United Kingdom will never take an action that will break the special relationship," Pompeo said.
On Venezuela, they did agree.
"It is disgusting to see leaders... who continue to support the murderous dictator Maduro," Pompeo said.
He said no Western leader should stand behind Maduro.