An anti-government protester stands near a road barricade in Kiev on Feb. 3, 2104. ANGELOS TZORTZINIS/AFP/Getty Images

Leaders of the anti-government protests that have gripped Ukraine's capital for more than two months said they will seek constitutional changes Tuesday that would weaken the president's powers. Meanwhile, Western officials are returning to the country this week in an attempt to resolve the political crisis, with help that could come partly in the form of a financial aid package currently under discussion between the United States and European Union. The constitutional changes were expected to be discussed in a parliamentary session Tuesday as Ukraine's political crisis continues unabated, with protesters still refusing to leave their encampment in downtown Kiev or vacate buildings they occupy. The demonstrators, who clashed with police last month, are holding to an uneasy truce. Opposition leader Arseniy Yatsenyuk said Monday that constitutional change would "cancel the dictatorial powers of the president and transfer the right of governing the country to the Ukrainian people." One protest leader, Oleh Tyahnybok, said the opposition would also push in parliament for a blanket amnesty for more than 100 people arrested in the protests. Parliament last week offered amnesty to some on the condition that protesters leave many of the buildings they occupy – but the opposition expressed disdain for that idea, saying authorities were essentially using the arrested as hostages.

"Cancel the dictatorial powers of the president and transfer the right of governing the country to the Ukrainian people."

Meanwhile, the U.S. is holding talks with the EU on drawing up a financial aid package for Ukraine, a U.S. official confirmed on Monday. "Let me be clear, this is at a very preliminary stage. We are consulting with the EU … and other partners about the support Ukraine may need after a new technical government is formed as the country gets back on the path to economic health through the IMF (International Monetary Fund)," U.S. State Department spokeswoman Jen Psaki told reporters. "Any decisions we make will be guided by events in Ukraine and our consultations with the new government after it is formed." The confirmation by U.S. officials that the U.S. and EU were discussing an aid package came after EU foreign policy chief Catherine Ashton told the Wall Street Journal that they were working together on a deal. Her spokeswoman, Maja Kocijancic, also said Monday that the EU is considering new financial measures to support Ukraine's troubled economy, but that the country's political crisis must be resolved before any assistance can be granted. Ashton is due to return to Ukraine Tuesday – her third diplomatic mission to Kiev since its crisis began – in a fresh bid to end the stalemate.

U.S. Assistant Secretary of State Victoria Nuland is also returning to Ukraine this week, in a new sign of U.S. support for the pro-democracy demonstrators, two days after Secretary of State John Kerry said he stood with Ukrainians "fighting for the right to associate with partners who will help them realize their aspirations." Meanwhile, European Commission President Jose Manuel Barroso said Monday that the 28-nation bloc is looking into providing additional financial assistance for crisis-ridden Ukraine – but that it does not want to start a bidding war with Russia to buy Kiev's allegiance. Barroso said Monday that Ukraine is facing "very huge challenges," and that the EU and its international partners are discussing what more can be done to help, provided Kiev will commit to reforming its economy in return. Barroso said that the EU's offer of a wide-ranging free trade deal remains on the table, and that its readiness to provide further assistance was not about entering a "bidding competition of who pays more for a signature from Ukraine."

Opposition vs. government