South African President Jacob Zuma and his ruling African National Congress party is hosting Hamas leader Khaled Mashaal this week for a four-day visit that has upset Israel. The governing party has vowed to build a long-lasting relationship with the Palestinian militant Islamic group and signed a letter of intent in Johannesburg Monday committing to work together against the ongoing Israeli occupation of Palestine, according to South Africa’s Radio Islam.

“We are starting a relationship with Hamas…we are happy today we are together, we are formally formalizing our relationship,” African National Congress Secretary-General Gwede Mantashe reportedly said Monday. “We’ll exchange delegations, we’ll share experiences and we’ll talk to each other regularly. We are discussing whether Hamas shouldn’t open an office in South Africa so we can talk.”

Mashaal met with South Africa’s president upon his arrival Sunday and will hold a public rally Wednesday in the capital Cape Town. The Hamas leader is accompanied on the trip by other senior members including Musa Abu Marzug and Mohammed Nazzal.

“We are insisting with our people to finish this apartheid regime. This racist occupation should be put to an end,” Mashaal said during a press conference Monday, according to the Middle East Eye.

The visit has been hailed by some South Africans as a “huge step for the country,” South Africa’s Radio Islam reported. Former South African President and African National Congress leader Nelson Mandela, an anti-apartheid revolutionary who died in 2013, was an outspoken supporter of the Palestinian cause and visited both Israel and Palestine, calling for peace between both sides.

Israeli officials, however, were outraged that South Africa’s ruling party was hosting the exiled Hamas chief. Israel’s Foreign Ministry spokesman Emmanuel Nachson said Monday the invitation to Mashaal to visit “gives support and encouragement for terrorism and pointedly ignores the position of the international community, which views Hamas as a terrorist organization,” according to the Jerusalem Post. Nachson said the ministry has called in South Africa’s deputy ambassador to protest the visit.

The South African Zionist Federation also issued a statement condemning the controversial visit to the country in “the strongest terms possible,” saying Hamas “has enthusiastically endorsed the cold-blooded murder of Israeli civilians and instigated dozens of lethal attacks against them.” The statement also said the ideology, values and goals of Hamas are “diametrically opposed” to those of South Africa’s governing party, the Jerusalem Post reported.

Hamas is a designated terrorist organization by the European Union, the United States, Israel, Egypt, Japan and Canada. The militant group is a nationalist-Islamic spin off of Egypt’s banned Muslim Brotherhood. Hamas seized control of the Gaza Strip in 2007, which was followed by deadly violence with Israel as well as the ousted Fatah government in the West Bank.