Pakistan's government announced its first major concession Saturday in a monthlong political crisis, pledging to appeal a disputed court ruling against a key opposition leader, just hours after a concerned U.S. Secretary of State Hillary Clinton called both sides, apparently to press for a resolution.

Both the country's pro-Western president, Asif Ali Zardari, and former premier Nawaz Sharif are under increasing pressure from the United States, which fears the year-old government is already bogged down in power struggles when it needs to focus on economic problems, as well as Western demands for more help with the faltering war effort in neighboring Afghanistan.

Sharif vowed to go ahead with mass protests planned for Monday in the capital, even as the government insisted it would enforce a ban, put troops on alert and warned terrorists could bomb the demonstration.

"This is a flood of people. This flood will break all hurdles. This flood will, God willing, reach its destination," Sharif, widely viewed as Pakistan's most popular politician, told cheering party workers in the eastern city of Lahore.

Nuclear-armed Pakistan lurched back toward turmoil last month when the Supreme Court disqualified Sharif and his brother from elected office, over convictions dating back to an earlier chapter in Pakistan's often vindictive political history.

Zardari compounded the crisis by dismissing the Sharifs' administration in Punjab, Pakistan's biggest and richest province.

Sharif then threw his support behind plans by activist lawyers to stage a mass sit-in Monday in front of Parliament in Islamabad to demand an independent judiciary. Zardari refuses to reinstate a group of judges, including the former Supreme Court chief justice, fired by former military leader Pervez Musharraf.

Clinton expressed concern about the crisis in phone calls with both Zardari and Sharif on Saturday, Pakistani officials said.

Clinton "urged a settlement through negotiations," Sharif spokesman Pervaiz Rasheed said.

The State Department declined to give any details.

Hours later, the government announced that it would appeal the Supreme Court ruling about the Sharifs in the coming week.

"This is part of the government's policy to resolve political issues through reconciliation and negotiation," spokesman Farhatullah Babar said. "We want to bring down the political temperature."

Sharif didn't address the concession in his speech.

Ishaq Dar, a party lieutenant, praised the appeal, saying "sense must prevail" in the face of Pakistan's mounting problems.

Still, he said the party would not compromise on its demand for the fired judges' return.

Many observers suspect Zardari fears the judges could challenge the legality of his rule and of a pact signed by Musharraf that quashed long-standing corruption charges against him and his wife, slain former leader Benazir Bhutto.

Skeptics suspect Sharif of hoping to force early elections, though critics warn he could end up prompting army intervention just a year after democratic elections ended former army chief Musharraf's long domination.

Sharif said he and his supporters would join lawyers in Lahore on Sunday before driving in convoys toward Islamabad.

Authorities have blocked the main road to Parliament with metal shipping containers and say they also have to protect nearby foreign embassies. The area is already a high-security zone.

In another sign of strains in the government, Information Minister Sherry Rehman announced her resignation from the Cabinet after the private Geo TV channel complained that cable TV companies had blocked its programming in several cities.

Geo accused Zardari of ordering the restrictions — an allegation his spokesman denied.

Rehman, who has often spoken in defense of media freedoms, didn't explain her decision, and the channel appeared to be available again on Saturday in major cities.

Police have temporarily detained scores of activists across the country, including five people at a gathering of hundreds of lawyers and Sharif supporters Saturday in the central city of Multan.

"So far our attitude is soft, but we can change our strategy," Ali Ahmad Kurd, the leader of the country's lawyers' movement, said in the southwestern city of Quetta after authorities allegedly prevented him from boarding a plane to Lahore. His road convoy was turned back by police a day earlier.

Army spokesman Maj. Gen. Athar Abbas said the government put the army on notice Friday that an unspecified number of troops might be needed to protect "sensitive areas" in Islamabad and elsewhere.

"When the situation deteriorates, gets out of hand of police, paramilitary, only then the army is deployed," Abbas told The Associated Press.