Consider the following statements.
UNESCO's World Heritage mission is to
1. Take over the management, maintenance and preservation of World Heritage sites.
2. Encourage state parties to the Convention concerning the Protection of the World Cultural and Natural Heritage to nominate sites within their national territory for inclusion on the World Heritage List.
3. Provide emergency assistance for World Heritage sites in immediate danger.
Which of the statements given above are correct?

To determine which statements about UNESCO's World Heritage mission are correct, let's evaluate each one based on UNESCO's official objectives and activities under the 1972 Convention Concerning the Protection of the World Cultural and Natural Heritage.

1. **"Take over the management, maintenance and preservation of World Heritage sites."**
- This statement is **incorrect**. UNESCO's World Heritage mission does not involve taking over the management, maintenance, or preservation of World Heritage sites. Instead, the responsibility for managing, maintaining, and preserving these sites lies with the State Parties (the countries where the sites are located). UNESCO provides guidance, technical assistance, and international cooperation, but it does not assume direct control over the sites.

2. **"Encourage state parties to the Convention concerning the Protection of the World Cultural and Natural Heritage to nominate sites within their national territory for inclusion on the World Heritage List."**
- This statement is **correct**. A key objective of UNESCO’s World Heritage mission is to encourage State Parties to nominate sites of outstanding cultural or natural value within their territories for inclusion on the World Heritage List. This is explicitly outlined in the Convention, which promotes the identification and nomination of sites for global recognition and protection.

3. **"Provide emergency assistance for World Heritage sites in immediate danger."**
- This statement is **correct**. UNESCO, through the World Heritage Fund, provides emergency assistance to World Heritage sites facing immediate threats, such as natural disasters, armed conflicts, or other crises. This assistance can include financial and technical support to help protect and stabilize endangered sites, as outlined in the Convention’s provisions for international assistance.

### Conclusion
The correct statements are **2 and 3**.

**Final Answer**: Statements 2 and 3 are correct.