The Transatlantic Trade and Investment Partnership (TTIP) is a proposed trade agreement between the European Union (EU) and the United States (US). Negotiations for the TTIP began in 2013 and although they have been controversial and slow-moving at times, the agreement is still being pursued by officials on both sides of the Atlantic.

If the TTIP is finalized and implemented, it will create the world`s largest free trade zone, covering approximately 60% of global GDP. The agreement aims to reduce tariffs and regulatory barriers to trade between the two regions, making it easier and more efficient for businesses to operate on both sides of the Atlantic.

There are currently 28 countries in the EU, which are all potential members of the TTIP. These countries include Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and the United Kingdom.

On the US side, there are 50 states and all of them are potential members of the TTIP. The US is currently negotiating the agreement through the Office of the United States Trade Representative (USTR), which is responsible for developing and implementing US trade policy.

In addition to the EU and the US, there are several other countries that have expressed interest in joining the TTIP. These countries include Canada, Mexico, and Japan. However, negotiations are currently only taking place between the EU and the US, and it is unclear whether any of these countries will ultimately become TTIP members.

The TTIP has been controversial for a number of reasons. Some critics argue that the agreement will result in job losses and increased inequality, as it will likely lead to outsourcing and decreased labor standards in the participating countries. Others are concerned about the potential impact on consumer safety and the environment, as regulatory standards may be lowered in order to facilitate trade.

Despite these concerns, the TTIP remains a priority for both the EU and the US. The agreement has the potential to increase economic growth and create jobs on both sides of the Atlantic, while also strengthening ties between the two regions. Whether or not the TTIP will ultimately be successful remains to be seen, but it is clear that it is a significant and complex undertaking that will continue to be debated and scrutinized in the coming years.