Masoud Pezeshkian officially became the new president of Iran after an oath-taking ceremony at the parliament in Tehran on Tuesday.

The oath-taking ceremony followed the formal endorsement of the new president by Supreme Leader Ayatollah Ali Khamenei on Sunday, in line with Article 110 of Iran’s Constitution.

The 69-year-old veteran reformist lawmaker and cardiac surgeon defeated his conservative rival and former security body chief, Saeed Jalili, in the presidential runoff election on July 5.

After being administered the oath by Parliament Speaker Mohammad Baqer Qalibaf, Pezeshkian delivered a speech outlining his domestic and foreign policy priorities.

He said the presidential election and formation of a new government has opened a "new opportunity" for Iran and the world, describing his Cabinet as a "government of national unity."

The new Iranian president asserted that the world must take advantage of this "unique opportunity" to resolve regional and global issues with the participation of a "powerful, peaceful, and dignified Iran."

Pezeshkian pledged that his government would pursue "fair and sustainable progress and development" for Iran and improve the economic situation and quality of life for the people of the country.

He also vowed to "firmly defend Iran's interests and rights" on the international stage, while prioritizing stronger relations with the neighboring countries, in line with the previous government.

"My government seeks a strong region where all neighboring countries can cooperate for economic development, progress, and the betterment of future generations, a region where security is ensured by the presence of regional countries," he said.

Pezeshkian also slammed Israel over its devastating offensive on the Gaza Strip, saying the "leader of a regime that fights women and children in Gaza and drops bombs on them" should not be applauded, referring to Israeli Prime Minister Benjamin Netanyahu’s recent address to the US Congress.

"One can’t call oneself human and remain silent in the face of so many atrocities," he said, calling for a world where the "people of Palestine are freed from occupation, oppression, and genocide."

In the coming days, the reformist president will introduce his council of ministers to the conservative-dominated parliament for approval, which experts say will be the first big challenge for him.

He has already named Mohammad Reza Aref, a veteran reformist politician, as his first vice president.