Pakistani officials appealed Friday to the opposition to join talks aimed at resolving the country's political crisis, even as police stepped up a crackdown on activists trying to reach the capital for a planned anti-government protest.

President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani met, and Zardari also spoke with army chief Gen. Ashfaq Parvez Kayani.

Officials declined to give details, but the talks came amid efforts to end a feud stemming from Zardari's refusal to reinstate a group of judges fired by his predecessor, Pervez Musharraf.

The turmoil has raised the prospect of another military coup and undermines American hopes that Pakistan will stay focused on the fight against Al Qaeda and Taliban extremists along its border with Afghanistan. U.S. envoys have been in touch with both sides.

Authorities have detained hundreds of political activists and lawyers in recent days, seeking to thwart demonstrators from converging in Islamabad, where they want to stage a sit-in Monday outside Parliament until their demands are met.

State Minister for Information Sumsam Bukhari told Express News television that the government was "ready to sit at the table ... but on the other side, sense is not prevailing."

"If they want reconciliation talks, we are ready for that," he said.

Speaking to Express, Zardari aide Farahnaz Ispahani said she hopes opposition leader Nawaz Sharif takes "a more moderate and less belligerent approach and comes forward and tries to deal with things."

Pakistan's lawyers have been long demanding reinstatement of the judges. Their movement intensified last month when the Supreme Court banned Sharif and his brother from elected office. The federal government then dismissed the Punjab provincial administration led by Sharif's brother, further stoking discontent.

Speaking to Geo television, Sharif insisted he is not trying to destabilize the government but urged the prime minister to reinstate the judges — even without Zardari's consent. Sharif also pledged the protests would proceed if authorities put him under house arrest.

Across the country, groups of activists have set off for the capital, but have met resistance in several areas.

Early Friday, police stopped about 200 lawyers in a convoy of cars and buses from entering Sindh province en route to Islamabad, witnesses and participants said. No arrests were made, and the protesters vowed to find another way to get to the capital.

The crackdown extended into Pakistan's North West Frontier Province, where officials with Sharif's party said Friday that a few dozen activists were detained. The provincial government announced a ban on rallies, joining Punjab and Sindh provinces.

Richard Holbrooke, an Obama administration envoy to Pakistan and Afghanistan, spoke by phone to Zardari and Gilani, while U.S. Ambassador Anne Patterson met Thursday with Sharif. There were no signs of a breakthrough.

Most of the judges fired by Musharraf have been restored to their posts, but the government has ignored a few, including the former chief justice. Zardari is believed to fear those judges could move to limit his power or reopen corruption cases against him. His supporters say the old chief justice has become a political figure and will no longer be neutral.