China has warned Taiwan's leaders to end what Beijing called their "lurch towards independence".
Mr Chen is keen to stand up to China's influence
The strongly worded statement came days before Taiwan's President Chen Shui-bian is due to be sworn in for a new four-year term.
As expected, Taiwan failed in its eighth bid to gain observer status at the UN health agency on Monday.
China opposed the bid because it views Taiwan as a breakaway province that should be re-united with the mainland.
In a statement carried by China's official Xinhua news agency, Beijing appealed to Chen Shui-bian to resume talks on uniting China and Taiwan.
"The Taiwan leaders have before them two roads. One is to
pull back immediately from their dangerous lurch toward
independence," said the statement issued by China's Office for Taiwan Affairs.
President Chen was only narrowly re-elected, prompting protests
"The other is to keep following their separatist agenda to cut Taiwan from the
rest of China and, in the end, meet their own destruction
by playing with fire," it said.
Much of the criticism was reserved for Mr Chen, who has steadfastly refused to endorse China's plans for unification.
It highlighted the recent Taiwanese referendum on whether Taipei should open talks with Beijing or beef up its defences.
Mr Chen went ahead with the referendum - held at the same time as the presidential elections in March - despite the obvious displeasure of Beijing.
Mr Chen "has tried every possible means to promote Taiwan
independence by way of referendum," the statement said.
"His track record... is one of broken promises and bad
The referendum failed because fewer than
the required 50% of the electorate voted on the issue, but Mr Chen was re-elected with a tiny minority.
He is due to be inaugurated for his second term in office on Thursday.
WHO observer status
Taiwan applied for observer status at the WHA ( the decision-making body for the World Health Organisation) as a "health entity" rather than a country.
It claimed it needed a link
with the health agency to help it fight diseases like last year's Sars virus.
But the WHA decided not to include the issue
on the agenda of its annual conference in Geneva.
Before the meeting, Taiwanese Health Minister Chen Chien-jen said he was hopeful that Taiwan would be granted its wish for observer status this year, despite many failed attempts.
"This year more and more people have realised our request is for the realisation of health for all," he told BBC News Online.
Taiwan's previous efforts to get a foothold into the WHO have been frustrated by China. Taiwan was forced to leave the organisation in 1972, a year after it lost its UN seat to Beijing.