By Louis Charbonneau

UNITED NATIONS, Sept 16 (Reuters) - Britain has circulated a draft resolution to members of the U.N. Security Council that would authorize naval operations aimed at seizing and disposing of vessels operated by human traffickers in the high seas off Libya, diplomats said on Wednesday.

The council received the draft on Tuesday, the diplomats said on condition of anonymity. They added that it could be put to a vote as early as next week, when the 15-nation council is expected to discuss the migration crisis.

The draft resolution would authorize members of the 28-nation European Union to capture smugglers in Libyan high seas and dismantle their boats to discourage migrants fleeing war and poverty in Africa and the Middle East.

The draft, seen by Reuters, would allow U.N. member states on high seas "to seize vessels inspected ... that are confirmed as being used for migrant smuggling or human trafficking from Libya." It adds that the boats' disposal "will be taken in accordance with applicable international law."

Such operations constitute the second of three phases of an EU naval mission intended to help stem the flow of migrants and refugees into the EU, which has escalated into a major international crisis in recent weeks.

Russian U.N. Ambassador Vitaly Churkin said in May that Europe should model its planned operations to tackle migrant smuggling across the Mediterranean from Libya on anti-piracy patrols in waters off Somalia, but he cautioned against destroying the boats used.

The authorization outlined in the draft resolution is a scaled-back version of an earlier plan to get U.N. authorization for all three phases of the operation - gathering intelligence, launching naval operations on the high seas off Libya and a final phase of operations off Libya's coast and on its shores.

Britain, diplomats say, is holding off on requesting authorization for the third phase of the operation because Libyan consent would be needed. But rival Libyan factions have yet to agree on power-sharing in U.N.-mediated talks.

While Russia is concerned about excessive use of force, diplomats say fellow veto power China is concerned about violations of sovereignty. But Western diplomats say there is no worry about sovereignty as the authorization covers the high seas.

The EU naval mission, which is already underway, is a joint operation of the Italian, German and British navies. Only Germany and Britain require U.N. authorizations for the seizure and disposal of vessels on high seas. (Reporting by Louis Charbonneau; Editing by Christian Plumb)