KHARTOUM, June 22 - China will send more than 200 troops to Sudan's Darfur region to help a joint African Union-United Nations peacekeeping force, its special envoy said in Khartoum on Friday.

"The government is planning to send 275 multipurpose, multifunction engineering troops to support the second phase of the Annan plan, the heavy support package," Liu Guijin told reporters in Khartoum, where he will meet President Omar Hassan al-Bashir and Deputy Foreign Minister Ali Karti on Saturday.

Former U.N. Secretary General Kofi Annan devised a plan that called for a 3-phase U.N. support package for the struggling African Union mission in Darfur.

Sudan accepted the first two phases of the plan, and earlier this month dropped its opposition to the third phase, which will involve the deployment of a joint U.N.-AU force of more than 20,000 troops and police.

The force will be under AU command and most troops will be African.

China said it encouraged, but did not put pressure on Sudan to agree to the plan. "We gave our advice to the Sudanese government as friends and brothers," Liu said.

"We are happy that they have taken our advice positively and they have shown their flexibility and they have shown their genuine political willingness to solve the Darfur issue."

The United Nations and African Union hailed the agreement as a breakthrough, but many observers remain sceptical, accusing Khartoum of signing deals and then wriggling out of them.