ISLAMABAD (AP) — A Saudi-led coalition targeting Shiite rebels in Yemen has asked Pakistan to contribute soldiers, Pakistan's defense minister said Monday, raising the possibility of a ground offensive in the country.

Defense Minister Khawaja Muhammad Asif made the comments as Pakistan's parliament debates whether to contribute militarily to the campaign against the rebels, known as Houthis. Pakistan previously offered its verbal support for the mission, but hasn't offered any military support.

Days of Saudi-led airstrikes have yet to halt the Houthi advance across Yemen, the Arab world's poorest country, fuelling speculation that there could be a ground operation launched in Yemen. Saudi Arabia and other coalition members have not ruled it out.

Saudi Arabia also asked for aircraft and naval ships to aid in the campaign, Asif said. He said Saudi officials made the request during his visit to Jeddah last week.

"I want to reiterate that this is Pakistan's pledge to protect Saudi Arabia's territorial integrity," Asif said. "If there's a need be, God willing, Pakistan will honor its commitment."

The Saudi-led campaign entered its 12th day Monday, targeting the rebels who took over the capital, Sanaa, in September and eventually forced President Abed Rabbo Mansour Hadi to flee. The rebels and allied forces are now making a push for Yemen's second-largest city, Aden, declared a temporary capital by Hadi before he fled abroad.

Muslim-majority Pakistan has close ties to Saudi Arabia, which is home to Islam's two holiest sites, Mecca and Medina. Pakistan also has a sizeable Shiite minority, complicating the debate over engagement in a conflict that is increasingly pitting Sunnis against Shiites.

The debate in parliament will aim to decide whether their country can afford to join the conflict in Yemen when it is already at war with Islamic and sectarian militants allied with groups like al-Qaida and Islamic State. Pakistan already has nearly 300 troops in Saudi Arabia taking part in joint exercises and most Pakistanis back the idea of protecting Islam's holiest sites from attack.

The Houthis have been backed by security forces loyal to Yemen's ousted President Ali Abdullah Saleh — whose loyalists control elite forces and large combat units in the country's military.

Yemen-based Al-Qaida in the Arabian Peninsula, considered among the most active and dangerous branch of global militant organization, has benefited from the crisis. The chaos also has disrupted a U.S.-led drone strike program targeting suspected militants there.