By Trevor Hunnicutt, Andrea Shalal and Kate Holton
WASHINGTON (Reuters) -U.S. President Joe Biden and British Prime Minister Rishi Sunak were expected to focus on deepening close economic ties between the United States and Britain as they gathered at the White House on Thursday, with Russia's war in Ukraine another big topic for the NATO allies.
The two leaders shared laughs and more sober sentiments in the Oval Office about the close relations between prior leaders from the two countries as they previewed topics for the meeting, including artificial intelligence, Northern Ireland as well as joint economic and security interests, including in Asia.
The meeting comes as Western officials try to ascertain whether Russia was responsible for the destruction of the Nova Kakhovka dam, which has displaced thousands of people and caused major economic and environmental damage. Ukraine and Russia have traded blame for the dam's destruction.
The two leaders will field questions at a joint news conference after their meeting, an opportunity not afforded to every world leader who visits the White House, and will also issue a joint statement, officials said.
"It's daunting to think if the conversations that our predecessors had in this room, when they had to speak of wars that they fought together, peace won together," Sunak told Biden.
"Again, for the first time in over half a century, we face a war on the European continent, and as we've done before the U.S. and the UK have stood together to support Ukraine."
Sunak joked that he would not create the same imposition on Biden that World War II-era British Prime Minister Winston Churchill did by allegedly wandering around the White House residence in the middle of the night when he was a guest of President Franklin D. Roosevelt.
Sunak brought Biden two gifts, a personalized Barbour jacket and a book written by an ancestor of Biden's in the 19th Century.
Biden and Sunak last met in Hiroshima, Japan, at the Group of Seven summit last month. They also met in Belfast in April and in San Diego in March at a trilateral event marking the defense partnership of the United States, Australia and Britain.
Thursday's discussion will touch on artificial intelligence safety, Britain said on Wednesday, saying it would host the first summit on the issue this autumn to discuss how the risks of AI can be mitigated through internationally coordinated action.
Sunak hopes to strengthen trading ties between Britain and the United States, keen to show some progress after the Biden administration quashed any speedy prospect of a post-Brexit free trade agreement between the two countries.
Britain has cemented deals with individual states and is hoping to reach other such "targeted agreements".
Sunak is also expected to try to win Biden's backing for defense minister Ben Wallace's bid to become the next secretary-general of NATO.
The British leader visited the U.S. Capitol on Wednesday, where he met with Republican and Democratic congressional leaders.
Sunak said on Wednesday a new alliance would help London and Washington protect supply chains and navigate a global economy where new powers are "manipulating global markets, withholding crucial resources and trying to establish a stranglehold over the industries that will define our future."
(Reporting by Trevor Hunnicutt, Andrea Shalal and Rami Ayyub in Washington, and Kate Holton in London; Editing by Lincoln Feast)