South Korea and Turkey are the latest countries that have decided to join the China-led Asian Infrastructure Investment Bank (AIIB), China's official Xinhua news agency reported.

As of 27 March, there are 37 countries and regions that have applied to become founding members of the $50bn (£31bn, €39.5bn) bank, which intends to finance Asia's rising infrastructure needs. The application deadline has been set for 31 March.

China's ministry of finance welcomed the decision and said South Korea will become a founding member by 11 April if other members approve, Xinhua said.

In October 2014, representatives of 21 Asian nations convened in Beijing to inaugurate the AIIB, which is focused on providing funding to infrastructure projects within Asia. The bank was initially capitalised with $50bn, half of which was funded by China. It is expected to be established by the end of 2015.

Britain became the first major Western country to apply to be an AIIB founding member, and was followed by major European nations France, Germany, Luxembourg, Switzerland and Austria. Xinhua noted that Britain's 12 March application was unexpected.

The decision of the countries, most of which are close allies of the US, comes despite warnings from the US over the AIIB's governance and environmental standards.

China has criticised the US stance on its venture, and addressed spreading concerns about its operation.

Earlier, the heads of the International Monetary Fund and the World Bank spoke in favour of the China-led initiative, dismissing worries that the emergence of AIIB would heighten competition in the international finance market.