By Steve Holland ‌and Michelle Nichols

WASHINGTON/UNITED NATIONS, Dec 12 (Reuters) - International troops could be deployed in the Gaza Strip as early as next month to form a U.N.-authorized stabilization ‍force, two ‌U.S. officials told Reuters, but it remains unclear how Palestinian militants Hamas will be disarmed.

The officials, speaking on condition of anonymity, said the International Stabilization Force (ISF) ⁠would not fight Hamas. They said lots of countries had expressed interest in ‌contributing and U.S. officials are currently working out the size of the ISF, composition, housing, training and rules of engagement.

An American two-star general is being considered to lead the ISF but no decisions have been made, the officials said. 

Deployment of the force is a key part of the next phase of U.S. President Donald Trump's Gaza peace plan. Under the first phase, a fragile ⁠ceasefire in the two-year war began on October 10 and Hamas has released hostages and Israel has freed detained Palestinians. 

"There is a lot of quiet planning that's going on behind the scenes right now ​for phase two of the peace deal," White House spokesperson Karoline Leavitt told reporters on Thursday. "We want ‌to ensure an enduring and lasting peace."

INDONESIA PREPARING TROOPS

Indonesia has said it ⁠is prepared to deploy up to 20,000 troops to take on health and construction-related tasks in Gaza. 

"It is still in the planning and preparation stages," said Rico Sirait, spokesperson of Indonesian Defence Ministry. "We are now preparing the organizational structure of the forces to be deployed."

Israel still controls 53% of Gaza, while nearly ​all the 2 million people in the enclave live in the remaining Hamas-held area. The plan - which needs to be finalized by the so-called Board of Peace - is for the ISF to deploy in the area held by Israel, the U.S. officials said. 

Then, according to the Trump peace plan, as the ISF establishes control and stability, Israeli troops will gradually withdraw "based on standards, milestones, and timeframes linked to demilitarization."

A U.N. Security Council resolution adopted on November 17 authorized a Board of ​Peace and countries working ‍with it to establish the ISF. Trump said ​on Wednesday that an announcement on which world leaders will serve on the Board of Peace will be made early next year.

DEMILITARIZING GAZA 

The Security Council authorized the ISF to work alongside newly trained and vetted Palestinian police to stabilize security "by ensuring the process of demilitarizing the Gaza Strip, including the destruction and prevention of rebuilding of the military, terror, and offensive infrastructure, as well as the permanent decommissioning of weapons from non-state armed groups."

However, it remains unclear exactly how that would work.  

U.S. Ambassador to the U.N. Mike Waltz noted on Thursday that the ISF was authorized by the Security Council to demilitarize Gaza by all means necessary - which means use of force. 

"Obviously ⁠that'll be a conversation with each country," he told Israel's Channel 12, adding that discussions on rules of engagement were under way. 

Hamas has said the issue of disarmament hasn’t been discussed with them formally by the mediators - the U.S., Egypt ​and Qatar - and the group's stance remains that it will not disarm until a Palestinian state is established.

Israel's Prime Minister Benjamin Netanyahu said in a speech on Sunday that the second phase would move toward demilitarization and disarmament.

"Now that raises a question: Our friends in America want to try and establish a multinational task force to do the job," he said. "I told them I welcome it. Are volunteers here? Be my guest," Netanyahu said. 

"We ‌know there are certain tasks that this force can perform ... but some things are beyond their abilities, and perhaps the main thing is beyond their abilities, but we will see about that," he said. 

(Reporting by Steve Holland and Michelle Nichols, additional reporting by Gribran Peshimam in Jakarta and Maayan Lubell in Jerusalem, Editing by William Maclean)