Hadi escaped from the capital, Sanaa, on Saturday after being under house arrest for a month following his resignation under pressure from Houthi rebels. After his escape, he released a statement declaring he is still President of Yemen, and calling all political decision made since September illegal and invalid.
The statement from the Gulf Cooperation Council Monday echoed Hadi, with council members stressing that all procedures taken by the Houthi after their coup were invalid.
According to two presidential aides, Hadi met Monday with an official Saudi delegation that informed him of Saudi Arabia's recognition of him as the constitutional President of Yemen.
Meanwhile the Gulf council -- whose member countries are the United Arab Emirates, Bahrain, Saudi Arabia, Oman, Qatar and Kuwait -- urged the U.N. Security Council to consider measures against the Houthis, and the council called on the Houthis to release Prime Minister Khalid Bahah along with government ministers who remain under Houthi arrest.
A nephew of the President was kidnapped Sunday by Houthi rebels, two security officials in Ibb province told CNN. The nephew, Nasser Ahmed Mansour Hadi, was heading to the seaport province of Aden, where the President fled after escaping from house arrest.
Tens of thousands of anti-Houthi protesters took to the streets Monday for the third continuous day in support of Hadi.
On Sunday, Sanaa saw large demonstrations calling for an end to the militant occupation of the city, and urging Hadi to stand against the Houthis.
"The Houthis thought they could not be stopped, and it only took hours for them to fall in the eyes of the people. Yemen has a President and the people will stand with him to uproot the Houthi militants from Sanaa," Ali Al-Saedi, a protest organizer in Sanaa, told CNN.
In Taiz, tens of thousands took to the streets to show support for the legitimacy of Hadi as President, and to condemn the continued Houthi takeover of the capital.
They carried placards reading "Out to militant rule, return of government institutions."
Last month, Houthis attacked the presidential palace and ministerial Cabinet, forcing both the President and Prime Minister to resign. Houthi militants then put Hadi under house arrest.
Since then, Houthis have failed to form a government or reach a deal with other political factions for the formation of a presidential council.
Resignation was never accepted by Parliament
The militants tightened their grip on power over the last month, but the House of Representatives has not met to accept Hadi's resignation.
Hours after Hadi fled Sanaa on Saturday, Houthi officials tried to force parliamentarians to meet immediately to accept his resignation, but their efforts failed.
On Monday, a senior aide to Hadi said the ousted President sent a letter to Yemen's head of Parliament asking that his resignation be withdrawn.
The ruling General People's Congress Party, headed by Yemen's former President Ali Abdullah Saleh, which holds a majority of seats in Parliament, said it will not push for a Parliament vote to accept the resignation of Hadi.
"Hadi is the President of Yemen, since his resignation has yet to officially reach Parliament. Yemen is still led by a constitutional elected President," said Abdul Aziz Jubari, the secretary general of the independent Justice and Building Party.
Houthis are Shiite Muslims who have long felt marginalized in the majority Sunni Muslim country. They had been at war with the central government for more than a decade, but their entry into Sanaa in September brought things to a head, sparking battles that left than 300 people dead before a ceasefire was agreed to that month. Houthis then pressured Hadi to step down last month after he refused to agree to certain political demands.
The Houthis' takeover of Sanaa stunned governments of Western nations, which pulled out diplomatic staff this month.
Foreign evacuation continued in the Yemeni capital as Egypt evacuated all its Embassy staff and closed its Embassy on Monday morning. Earlier this month, the United States, along with most European and Gulf countries, suspended operations in their embassies in Yemen amid growing unrest.