Saudi King Salman bin Abdulaziz Al-Saud vowed that low oil prices would not halt progress in his country, and promised to defend Arab and Muslim causes around the world in his first major policy speech since assuming the throne.

In Tuesday's televised address, King Salman also promised improvements in education and healthcare, and to find solutions for affordable housing shortages.

In an acknowledgement of the kingdom's burgeoning young population, the 79-year-old monarch urged businesses to help create jobs, calling it a national duty.

King Salman assumed the throne in January after King Abdullah's death.

"Every citizen in the country and every region of our nation are of my concern, interest and care," King Salman said, adding that all Saudis are equal before his eyes.

Throughout the speech, he addressed both men and women, referring to them as "brothers and sisters" and "my sons and daughters".

The conservative country has been criticised for its limited women's rights.

Further than the much-publicised prohibition of women to drive, every woman in Saudi Arabia must have a male guardian - usually a husband or father, sometimes a son. Women have to seek permission from their guardian to travel, work, marry or make many other decisions.

The country's Shia minority has also complained of widespread discrimination.

Oil prices falling

Saudi Arabia is the world's second-largest oil producer, and King Salman said the kingdom would continue oil and gas exploration.

Oil prices dropped by half in the second half of 2014, but Saudi Arabia's massive cash reserves have enabled it to press on with development.

The Ministry of Finance predicted an increase in overall spending for 2015, despite a resulting $38.7bn budget deficit expected.

Some analysts have suggested that Saudi Arabia is leveraging low oil prices to place pressure on oil-based economies that do not have the same cash reserves as the country.

King Salman also warned that security threats would be dealt with severely.

"Security is a blessing and a pillar for the prosperity of a society and its stability," Salman said. "Security is the responsibility of all and we will not permit anyone to tamper with it or our stability."

At the beginning of last year Saudi Arabia passed a new terrorism law, meant to deal with increased security concerns over radicalisation due to the conflict in Syria.

The law allows strict sentences for Saudis that fight in conflicts outside the country, but also contained provisions punishing anyone found to "insult the reputation of the state".

However, human rights organisations have criticised the law for allowing the government to crack down on all dissent under the guise of fighting "terrorism".

On foreign policy, King Salman said his country "would continue to defend Arab and Islamic issues" and the creation of a Palestinian state with Jerusalem as its capital.