Pakistan (search) has won praise from the United States government for its investigation into a scientist's sale of nuclear technology to Iran, Libya and North Korea.

Secretary of State Colin Powell (searchexpressed his "appreciation" of the investigation in a phone call Saturday to President Gen. Pervez Musharraf, Foreign Ministry spokesman Masood Khan said Sunday.

Powell has also said he plans to visit the country, an official said.

The United States has declined to publicly criticize Islamabad over the transfer of secret technology by the founder of the Pakistan's nuclear program, Abdul Qadeer Khan (search).

Instead, Washington has praised the investigation and called Musharraf's decision last week to pardon Khan after the scientist's televised apology an internal matter.

Musharraf, who seized power in 1999, is a key U.S. ally in the war on terror, but his alliance with Washington has prompted criticism at home, and Islamic extremists were blamed for two assassination attempts against Musharraf in December.

In a phone conversation Saturday, Powell "called to convey the United States' appreciation over the results of the investigations and the manner in which they were conducted," the Foreign Ministry spokesman said.

In response, Masood Khan said Musharraf "reiterated Pakistan's resolve that no such activity will be allowed to take place in the future."

Powell plans to visit Pakistan "shortly," a top government official told The Associated Press on condition of anonymity.

Meanwhile, Pakistan's foreign minister said Sunday that foreign intelligence had years ago passed on information about Abdul Qadeer Khan giving nuclear technology to other countries — prompting his removal in 2001 as head of the Khan Research Laboratories, the main nuclear lab named after him.

Musharraf took action "because some of our friends' intelligence agencies shared some information with us," Khursheed Kasuri told an international security conference in Munich, Germany. He did not elaborate.

After losing his job at the lab, Khan was appointed as a top government adviser, a post he was fired from last week in the wake of the proliferation scandal.

Pakistan apparently made no moves to further investigate and still publicly denied the allegations of proliferation that had dogged Khan and the country for years. "There was smoke, fire had not yet been discovered," Kasuri said.

Musharraf has strongly denied any official involvement in proliferation, but many are skeptical that the technology could have been transferred without at least tacit official approval.

The latest probe began in late November after the U.N. nuclear watchdog also revealed evidence about the spread of Pakistani nuclear technology.

A local newspaper, The News, reported Sunday that Pakistan was pressured to launch the investigation after top U.S. officials confronted Musharraf in October with evidence detailing Khan's black market contacts, warning that Islamabad's relations with Washington and the world would suffer if no action was taken.

U.S. intelligence had documented Khan's travels to the United Arab Emirates, Malaysia, Libya, Iran and North Korea, and had details of meetings with black market figures, documents and bank account information, according to the report.

U.S. officials also mentioned Khan's attempts to sell nuclear secrets to Saddam Hussein and a meeting in Lebanon with a top Syrian government official, the newspaper said. Both countries turned down Khan's help.

Officials declined to comment on the report.