COLOMBO (AFP) - China warned the United States not to "coerce and bully" Sri Lanka as US Secretary of State Mike Pompeo arrived on a sensitive visit seeking to draw the strategic island away from Beijing.

Pompeo is expected to ask Colombo to make "difficult" choices on its relationship with China, which has provided key investment and diplomatic backing in recent years.

"We are firmly opposed to the United States taking the opportunity of the State Secretary's visit to sow and interfere in China-Sri Lanka relations, and to coerce and bully Sri Lanka," China's embassy said in a statement.

Pompeo arrived from India where he stepped up anti-Chinese comments which are expected to be a theme of an Asian tour that will take him on to the Maldives and Indonesia.

The top US diplomat for South Asia, Dean Thompson, said before the tour that Pompeo will ask Sri Lanka to review options offered by Washington.

Education minister Gamini Peiris denied opposition claims that the visit was to finalise a controversial military pact that would allow US troops free access.

"There are no agreements to be signed," Peiris told reporters.

In talks with President Gotabaya Rajapaksa on Wednesday, Pompeo will highlight Sri Lanka's importance as an Indo-Pacific partner on security and economic issues, US officials said.

"He will also emphasise our commitment to Sri Lanka's sovereignty and encourage progress on governance and reconciliation priorities," a State Department official said.

Earlier this month, Yang Jiechi, a Chinese Community Party politburo member, pledged more economic help to Sri Lanka during a visit.

Colombo has leaned heavily on China for loans and diplomatic support to fight off allegations of human rights violations, particularly in the final months of a decades-long civil war in 2009.

Washington has insisted on credible investigations into charges that Sri Lankan troops killed at least 40,000 civilians while crushing Tamil Tiger rebels.

Rajapaksa was the island's top defence official and his brother Mahinda was president when the final onslaught was carried out. Mahinda is now prime minister.

Pompeo's visit went ahead despite a surge in coronavirus lockdowns in many parts of Colombo because of a surge in infections.

This includes an area where Pompeo is to visit a Catholic church which was hit by a suicide bomber last year. Pompeo is to place a wreath at St Anthony's where 56 people were among 279 killed in coordinated Easter Sunday suicide bombings on three churches and three hotels.