UNITED NATIONS (Reuters) - U.N. Secretary-General Kofi Annan called on all members of the deadlocked 15-nation U.N. Security Council on Thursday to work together to break an impasse over how to ensure Iraqi disarmament.

Annan also said that Prime Minister Tony Blair had assured him this week that Britain was genuinely searching for a way forward on Iraq that could lead to peaceful disarmament rather than seeking a hidden trigger for war, as suggested by France and Russia.

"I know that strenuous efforts are being made by council members to compromise and break a deadlock. I think these efforts should be taken seriously and I would urge all council members to cooperate and to work in search of that compromise," Annan told reporters.

"I think what is important (is) that governments have to find a way of working together. Regardless of how this crisis ... is resolved, the council will have to work together and the member states will have to work together to deal with the situation in Iraq, in the Middle East and in many other issues," he said.

Britain has proposed an informal list of tasks Iraq would have to carry out to convince the Security Council that it was fully committed to ridding itself of any weapons of mass destruction, as demanded by council resolutions.

The goal of the British proposal is to attract more support to a draft resolution backed by the United States, Britain and Spain that would require Baghdad to demonstrate its full commitment to disarmament by March 17 or face war.

Annan said that in his conversation with Blair, which took place on Monday, the British leader "seemed very genuinely looking for a compromise and a way forward."

Blair "indicated to me that if, in his judgment, Saddam Hussein and the Iraq leadership were to meet the criteria or the tasks set, and one were to conclude that he was genuinely disarming, we should accept it. And of course if he failed, then the consequences should follow," Annan said.

He also noted that he had received a suggestion from Brazilian President Luiz Inacio Lula Da Silva that the United Nations convene a summit of world leaders who are not Security Council members to help search for a compromise acceptable to all sides.