* The war in Ukraine is expected to be a key topic of discussion, with Britain having led the West in supplying arms to Kyiv to fight against Vladimir Putin's invasion.

* The two leaders will also discuss the growing threat from China, artificial intelligence, and Mr. Biden's inflation reduction act.

* The meeting aims to move beyond the tensions caused by the UK's confrontational approach to Brexit and the Northern Ireland trade row.

* During the visit, Sunak laid a wreath at Arlington National Cemetery and met with key congressional leaders, business leaders, and watched a Major League Baseball game celebrating US-UK ties.

* The ceremonial first pitch was thrown by a British army veteran instead of Sunak, as it was deemed more appropriate to highlight the relationship between the two countries, particularly focusing on service personnel and veterans.

* Ahead of the talks, there was a fresh frenzy in Washington over Donald Trump's bid for a return to the White House.

UK and US leaders are set to discuss the Malaysia Airlines Flight MH17 downing, as well as other issues including artificial intelligence, at a meeting today.

Britain is assessing the evidence regarding Russia's involvement in the incident, which would be considered an "appalling barbarism" if proven intentional.

The two countries are also working on a project to train and equip Ukrainian pilots on F-16 fighter jets.

The UK will host a global summit on AI safety later this year, and the leaders will discuss joint US-UK leadership on critical emerging technologies and how to strengthen economic security.

The UK's detailed and measured approach to issues, including the Windsor Framework deal on Northern Ireland trade, is being well-received in Washington.

The US-UK free trade deal is not expected to be a major part of the discussions, and the chairs of the congressional-executive commission on China have asked Sunak to work with the Biden administration on Hong Kong policy and push for the release of activists.