The appeal came as political party leaders and activists gathered in the Algerian capital for a new round of UN-mediated peace talks aimed at reaching an accord to end the chaos and violence at home.
Libya's controversial army chief, Khalifa Haftar, visited Jordan where King Abdullah II pledged Amman's support in his fight against Islamist "terrorists" in the east of the country.
Since a 2011 revolt that toppled dictator Moamer Kadhafi, Libya has been politically divided, with two governments and two parliaments, as armed groups battle for its oil wealth and cities.
Most of the international community recognises the government and parliament based in the eastern city of Tobruk.
A rival administration in Tripoli emerged after Islamist-backed militias seized the capital last August.
Feeding on the chaos, the Islamic State jihadist group which holds chunks of Syria and Iraq has gained a foothold in the North African country, where its has claimed several deadly attacks.
Gunmen opened fire on South Korea's embassy compound from a passing car on Sunday, killing two Libyans and wounding a third.
Hours later, a bomb exploded outside the Moroccan embassy, causing no casualties but damaging cars, a security official.
Both attacks were claimed by the Tripolitania branch of IS.
"We will strike with an iron fist the dens of terrorists and all those who undermine security in the capital," Mahmud Abdulaziz, a member of the Tripoli-based parliament, told AFP.
A security official said that "increasing numbers of checkpoints" would be set up across Tripoli in a bid to restrict the jihadists' ability to carry out attacks.
Abdulaziz appealed to the international community to "help us fight Daesh," using an Arabic acronym for IS.
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"The world doesn't recognise us while we are fighting Daesh on behalf of the world," he said.
The government based in the eastern city of Tobruk condemned the attacks on foreign embassies, saying they indicate that Tripoli "has been hijacked by terrorist gangs".
- Violence harms talks -
In Algeria, Libya's UN envoy, Bernardino Leon, warned in remarks to a meeting of political party leaders and activists that violence hinders peace efforts.
"We think we are close to a political solution for Libya," said Leon, stressing the importance of the meeting aimed at a "draft agreement" on setting up a national unity government.
"We still have to send a message to those fighting, they must give us a chance to try to find a political solution," he said, offering condolences to families of the Tripoli attack victims.
Foreign ministers from Britain, France, Germany, Italy, Spain and the United States called in a joint statement on Libya's rival factions to agree on an "unconditional" ceasefire at their talks.
A source from the Tobruk government said the civilian killed in the attack on the South Korean embassy was the brother of Mahmud Jibril, who headed an interim government during the Libya revolt.
The South Korean foreign ministry said three of its nationals -- two them diplomats -- were in its compound at the time of the shooting.
The Moroccan foreign embassy condemned the bombing of its embassy -- which was shuttered like many others in Tripoli -- and demanded a probe into the "vile, criminal aggression".
In Amman, Haftar, seeking support for a campaign launched last May to retake the eastern city of Benghazi from Islamist groups, was told by the Jordanian monarch that Amman backs Libyan efforts.
Abdullah "stressed Jordan's continued support for Libya in its efforts to restore security and stability in the country and confront terrorist groups that threaten its sovereignty and the unity of its people," the palace said.