President George W Bush will host German Chancellor Angela Merkel at his Texas ranch to discuss unity on Iran's nuclear program, despite Tehran's defiance. The invitation to Crawford, Texas, signifies a close relationship, and Merkel will spend two days at the ranch engaging in talks on various global issues, possibly going hiking as well. This visit follows a similar treatment of French President Nicolas Sarkozy, who toured Mount Vernon earlier in the week. Bush, with limited time left in office, is focused on maintaining pressure on Iran regarding its nuclear activities. Iran has rejected the United Nations' request to stop its nuclear activities, which could be used for both civilian and military purposes. Iranian President Mahmoud Ahmadinejad claims that Iran's nuclear program cannot be reversed and that the country has 3,000 centrifuges at the Natanz plant. While German companies continue to do business with Iran, the United States has increased its opposition to Tehran. The White House National Security Council spokesman, Gordon Johndroe, stated that strategically they agree but there are some minor tactical differences. Earlier in the week, Merkel announced that Germany would back stricter UN sanctions against Iran if they did not address concerns about their nuclear program. Bush has also increased his criticism of Iran, mentioning the possibility of World War Three if they were to acquire nuclear weapons, which caused concern among some European allies. The Bush administration claims to be dedicated to pursuing diplomacy, while also keeping all options open. Perino stated that the two leaders would discuss working together diplomatically to urge Iran to stop uranium reprocessing and enrichment. Additionally, they will talk about various other topics such as Afghanistan, the Middle East, Iraq, climate change, and economic issues like the Doha trade round. According to a senior German official who spoke anonymously, Merkel and Sarkozy have decided to express a unified stance on Iran, the Middle East peace process, and climate change in talks with Bush. It is anticipated that a meeting will be held this month with Britain, China, France, Germany, Russia, and the United States to review reports from the International Atomic Energy Agency regarding Iran's adherence to global demands. Daniel Benjamin, a Brookings Institution analyst, noted that relations between the U.S. and Germany have seen improvement since Merkel succeeded Gerhard Schroeder.