The leading countries in AI research and development are constantly evolving, but as of now, the top 10 countries are:

1. United States: The U.S. is considered the global leader in AI research and development. It has numerous prestigious institutions, tech giants, and government initiatives dedicated to advancing AI.

2. China: China has significantly invested in AI research and development in recent years. It has a vast pool of tech companies, research institutes, and government support, aiming to become a global AI leader.

3. United Kingdom: The UK has a strong AI research community and notable academic institutions. Its government has prioritized AI development and funding, contributing to its position in the top rankings.

4. Germany: Known for its engineering expertise, Germany has been actively investing in AI research. It has strong industry-academia collaboration and government initiatives focused on AI advancements.

5. Canada: Canada has become a prominent player in AI research, driven by top universities and research institutions. It also actively attracts AI talent globally, making it a thriving hub for AI development.

6. France: France has a flourishing AI ecosystem with strong academic involvement, research institutions, and governmental support. It aims to position itself as an AI leader within Europe.

7. Japan: Japan has a long history of AI research and development. It has renowned universities and companies that focus on cutting-edge AI technology, particularly in robotics and automation.

8. South Korea: South Korea has made remarkable advancements in AI, thanks to its highly skilled workforce and strong government support. It has launched strategic plans to drive AI innovation across various industries.

9. Netherlands: The Netherlands has emerged as a leader in AI, with extensive government support and significant investments in AI research. Dutch universities and companies have been at the forefront of AI developments.

10. Sweden: Sweden has a thriving AI ecosystem, with a focus on research, innovation, and applications. The country has made substantial investments in AI, particularly in areas like machine learning and robotics.

It is worth noting that AI research and development are dynamic fields, and the rankings may change over time as other countries intensify their efforts and make significant progress in this domain.