ISLAMABAD, Pakistan — China has agreed to immediately provide 50 JF-17 fighter jets to Pakistan, a major outcome of a visit by Prime Minister Yousaf Raza Gilani to Beijing this week, Pakistani officials said Thursday.

China and Pakistan have jointly produced the JF-17 aircraft, but the new planes would be equipped with more sophisticated avionics, the officials said. The latest jet fighters would be paid for by China, they said.

The announcement came as Pakistan’s already tense relations with the United States soured further after the killing of Osama bin Laden deep inside Pakistan on May 2.

Last week, Pakistan’s spy chief denounced the United States in a rare briefing before Parliament in which he condemned the American raid for breaching Pakistan’s sovereignty. Parliament, in turn, called for the government to revisit relations with the United States.