Lausanne, March 30 (IANS) The World powers negotiating a nuclear deal with Iran have gone on the overdrive to clinch a framework agreement before the March 31 deadline, with the US, German and French representatives cancelling travel plans to attend the talks. US Secretary of State John Kerry cancelled a planned return to the US to attend an event ho**uring his late Senate colleague Edward Kennedy, to ensure that he could attend Sunday's talks in the Swiss city of Lausanne, the US state department said, according to a BBC report. German Foreign Minister Frank-Walter Steinmeier and his French counterpart Laurent Fabius also delayed a planned trip to Kazakhstan in order to focus on the negotiations. They were joined by Chinese Foreign Minister Wang Yi and British Foreign Secretary Philip Hammond.