U.S. President Barack Obama has wrapped up a visit to London by urging the West to continue applying pressure on the Islamic State (IS) extremist group in the Middle East.
Speaking on April 24, Obama said he believes the territory the IS group holds can be slowly shrunk and that it can be driven from its stronghold cities of Mosul in Iraq and Raqqa in Syria.
The United States leads an international coalition that is bombing IS in Iraq and Syria.
Obama also said it would be a mistake for the United States, Britain, or any other Western states to use ground troops to overthrow Syrian President Bashar al-Assad.
He said that instead Western countries can apply international pressure upon other parties, including Iran and Russia, to help broker political transition in Syria.
Obama also spoke about Britain's upcoming referendum in June on whether to leave the European Union.
He told the BBC that quitting the EU would leave London out of a new trade deal Washington is negotiating with the bloc.
"The U.K. would not be able to negotiate something with the United States faster than the EU," he said.
Obama also said that by leaving the EU, the United Kingdom would "have less influence in Europe and as a consequence, less influence globally."
Part of the reason for Obama's visit to Britain has been to let the British public hear reasons why he feels leaving the union would be harmful for London.
Obama is due to fly later in the day to Hannover, Germany, where he will visit German Chancellor Angela Merkel.
The U.S. leader's visit to Hannover is ostensibly to open the northern German city's industrial trade fair, where the United States will be a partner nation for the first time.
After joining Merkel for a tour of the fair on the morning of April 25, Obama and the chancellor will attend a summit that will include the leaders of France, Italy, and Britain.
Obama's meeting with Merkel as well French President Francois Hollande, Italian Prime Minister Matteo Renzi, and British Prime Minister David Cameron will focus on counterterrorism efforts following attacks in Paris and Brussels, the White House has said.
The talks will also include the fight against IS militants in Iraq and Syria, the European refugee crisis, and Libya.
Obama's visit to Germany is the last stop on a six-day foreign journey where Obama has sought to shore up U.S. alliances he views as key to defeat IS militants, offset Russian aggression in Ukraine, and grow international trade.
