President George W Bush will host German Chancellor Angela Merkel at his Texas ranch to discuss unity on Iran, despite Tehran's defiance over its nuclear program. Bush invited Merkel to Crawford, Texas, as a symbol of their special relationship, where they will spend two days at the ranch engaging in talks on global issues and possibly going hiking. White House spokeswoman Dana Perino stated that the Western White House is a great setting for both social visits and in-depth discussions. Merkel is the second European leader to receive special treatment from Bush this week, following French President Nicolas Sarkozy's visit to Mount Vernon. As his time in office winds down, Bush remains focused on pressuring Iran regarding its nuclear activities. Iran has rejected the UN's request to stop its nuclear activities, which could be used for civilian or military purposes. Iranian President Mahmoud Ahmadinejad has stated that Iran's nuclear program cannot be reversed and has revealed that there are 3,000 centrifuges in the Natanz plant. While German companies continue to trade with Iran, the United States has adopted a tougher stance towards Tehran. The spokesman for the White House National Security Council, Gordon Johndroe, has mentioned that strategically they agree, but there are some tactical differences. Earlier this week, Merkel stated that Germany would back tougher UN sanctions against Iran if they do not address concerns about their nuclear program. Bush has also criticized Iran, warning of the possibility of World War Three if they acquire a nuclear weapon, which has concerned some European allies. The Bush administration maintains that they are committed to diplomacy but are keeping all options open. Perino mentioned that the two leaders will discuss Iran and the importance of working together diplomatically to stop Iran's uranium activities. They will also cover topics such as Afghanistan, the Middle East, Iraq, climate change, and economic issues like the Doha trade round. A high-ranking German official, speaking anonymously, mentioned that Merkel and Sarkozy have decided to present a unified stance on Iran, the Middle East peace process, and climate change when discussing with Bush. It is anticipated that Britain, China, France, Germany, Russia, and the United States will convene this month to review reports from the International Atomic Energy Agency regarding Iran's adherence to international requirements. Analyst Daniel Benjamin from the Brookings Institution noted that relations between the U.S. and Germany have seen improvement following Merkel's succession of Gerhard Schroeder.