The Papua New Guinea government is to send troops to guard two major resources projects on Monday after people disrupted work at the sites, the prime minister's office said in a statement.

The troops will be deployed at Exxon Mobil's $15.7 billion liquefied natural gas (LNG) project in the Southern Highlands province and Barrick Gold's Porgera gold mine in Enga province.

"It is totally unacceptable that law and order has broken down in those areas," the office of Prime Minister Peter O'Neill said in a statement.

"Such behaviour has placed the lives of innocent people at risk, and disrupting work at the LNG project and operations at a mine that is a key contributor to the national economy."

The office did not say how many soldiers would be sent.

Work at a part of Exxon's gas export project, known as PNG LNG, was stopped for about two weeks last month after landowners demanding additional compensation for their land stormed a work site and threatened workers.

Illegal miners stopped work at Barrick's Porgera open pit gold mine late last week, attacking workers and damaging equipment, prompting Barrick to ask the government to intervene, the prime minister's office said.

The National Executive Council approved sending troops to PNG LNG last week, while the troops are being sent to Porgera under a troop call-out order from 2009 which is still in effect.

The Porgera gold mine is 95 percent owned and operated by a Barrick subsidiary, with the remainder owned by the Papua New Guinea government.

Exxon's LNG project is a joint venture between Exxon Mobil, Oil Search, Santos, Japan's JX Nippon Oil and Gas Exploration, a unit of JX Holdings, and the Papua New Guinea government.