New Delhi, Sept. 11 -- A US delegation is set to visit India next week for negotiations on selling six more P-8I maritime patrol aircraft to the Indian military as background contacts continue between the two sides to get bilateral relations back on track after a trade row, people familiar with the matter said on Wednesday. The American team, comprising senior officials of the defence department and Boeing, the manufacturer of the P-8 Poseidon aircraft already in service with the Indian Navy, will visit at a time when senior officials of the Trump administration have repeatedly excoriated India for buying Russian military hardware. While US President Donald Trump's decision to double tariffs on Indian goods by imposing a 25% punitive levy over Russian oil purchases has led to strains in bilateral ties not witnessed in almost two decades, signs have emerged of the two sides working to repair the relationship. On Wednesday, Prime Minister Narendra Modi and Trump had their second positive exchange on social media in four days, with both leaders pointing to the early conclusion of trade negotiations. The delegation from the US defence department and Boeing will visit Delhi during September 16-19 for detailed discussions on the current offer to the Indian government on procuring six P-8I aircraft, the people said on condition of anonymity. The delegation will include senior US officials handling relations with India from the office of the undersecretary of defence for policy, Navy International Programs Office (NIPO), Maritime Patrol and Reconnaissance Aircraft Program Office (PMA 290), and Defense Security Cooperation Agency (DSCA), the people said. NIPO oversees global maritime partnerships by focusing on export and transfer of capabilities that support the strategic security interests of the US, while PMA 290 manages the acquisition, support and delivery of maritime patrol aircraft. While the final cost of the six aircraft will be hammered out during negotiations, the people said the deal will be in the range of about $4 billion....