As part of the trip, Lord Cameron was due to hold a series of bilateral meetings - he was expected to speak with US Secretary of State Antony Blinken, as well as Republican and Democratic members of Congress.
According to the UK Foreign, Commonwealth and Development Office (FCDO), the former prime minister's discussions will focus on supporting Ukraine in its fight against Russian aggression.
It comes after Joe Biden urged Congress to pass his national security supplemental request, including funding to support Ukraine, earlier on Wednesday.
The US president's administration has warned Congress that money for the European country will run out by the end of the year as Russia's invasion continues.
Earlier this week, Mr Biden's national security adviser Jake Sullivan declared that not passing the additional aid would “make it easier for Putin to prevail."
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies